forwards addl info re ie bulletin 80-11, 'masonry wall design,' in … · 2012-12-06 ·...

DOCKET NO. 50-263. NSPC.. .MONTICELLO

ADO INF() RE IE BULLETIN 80-11

MASONRY WALL DESIGN.

Rec'd w/ltr 6/30/82 ..8207120023

HE A NOTICE THE ATTACHED FILES ARE OFFICIAL RECORDS OF THE DIISONOFDOUMN CONTROL. THEY HAVE BEEN CHARGED TO YOU FOR A LIMITED TIME PERIOD AND. MUST BE RETURNED TO THE RECORDS FACILITY BRANCH 016 PLEASE DO NOT SED DOCUMENTS CHARGED UT ROMUGH THE MAIL. REMOVAL OF ANY PAG -S)FRM DOCUMENT FOR REPRODUCTION MUST BE REFERRED TO FILE PERSONNEL.

DEADLINE RETURN DATE

6XJf~

RECORDS FACILITY BRANCH

I

Director of.NRR June 30, 1982 Enclosure (1)

1.0 NRC COMMENT

With reference to the response on page 2 of reference 3, show through sample calculations that the use of equivalent unreinforced walls in the analysis of reinforced walls will yield conservative results.

RESPONSE

The field survey on IE Bullletin 80-11 for the Monticello Nuclear Generating Plant located ten walls that were reinforced in both horizontal and vertical directions. Of the ten walls, six were in the Control Building, three in the Turbine Building, and one in the Reactor Building. The majority of the remaining walls were found to have horizontal joint reinforcement only.

The criteria for reevaluation was based on the assumption that the allowable stresses for tension both parallel and normal to the bed joint were such that the wall would remain uncracked at these levels of allowable stresses. Furthermore, the reinforcement in a reinforced masonry wall does not contribute to the resistance of applied loads until the wall section cracks. Thus the reinforcement provides a backup resistance activated when the wall cracks by exceeding the allowable stresses for an unreinforced wall.

Of the ten reinforced walls, the analysis showed six resisted the applied loads without cracking, i.e., did not exceed the unreinforced allowable stresses. Two cracked along the bed joints and two cracked both along the bed joints and perpendicular to the bed joints. The four walls that cracked did so over less than half of their surface area.

The four reinforced walls that the analysis showed would crack had the uncracked and cracked properties listed in Tables 1 and 2, respectively.

To calculate the frequencies and resulting forces on the cracked walls, the following procedure was used. The initial analysis of the uncracked walls were used to estimate the extent of cracking in the wall. The cracked areas were then assigned the orthotropic properties of the cracked walls given in Table 2 and reanalyzed. This process was repeated until the full extent of cracking was determined. Table 3 gives the respective first mode frequencies for the four walls in the uncracked, partially cracked and fully cracked state.

1-1

The four reinforced walls analyzed by this procedure all had adequate capacity to resist the applied seismic forces in the partially cracked state.

Table 3 - FREQUENCIES

Fundamental Frequencies Wall Uncracked Partially All Surface I.D Cracked Area Cracked

(Hz) (Hz) (Hz)

532 9.05 5.49 2.63 C105 12.89 7.62 4.15 C107 14.55 10.21 4.69 Cll0 10.85 5.22 3.36

The masonry walls at the Monticello Nuclear Generating Station were reevaluted on the basis that all walls were unreinforced. The allowable stresses for the reevaluation of the reinforced walls were based on the premise that the walls would remain uncracked if the allowable stresses were not exceeded. If a wall did not meet the criteria, but had two-way or at least vertical reinforcing, it was analyzed further. Four walls fell into this category. If a wall, on the other hand, did not meet this criteria and did not have at least vertical reinforcing, it was checked by alternate means.

For the four reinforced walls that were shown to crack, the extent of cracking was studied and the walls reanalyzed with reduced stiffness properties for the cracked regions. The four walls analyzed with this procedure were found to meet the criteria for reinforced walls.

The allowable moment capacity of 6" and 8" verticaly reinforced masonry walls is at least 4.0 to 4.9 and 3.2 to 5.1 times greater, respectively, than that of an equivalent unreinforced, ungrouted wall. Similar values for horizontally reinforced masonry walls are 2.3 and 1.8 times greater moment capacity for 6" and 8" walls, respectively.

Based on the assumptions and criteria used to reevaluate the masonry walls at the Monticello Nuclear Generating Station, the presence of reinforcement will not have any adverse effect. In fact, the presence of vertical and horizontal reinforcement will provide an additional factor of safety if the wall cracks when subjected to applied loads.

S1-2

4,

TABLE 1

FREQUENCY OF WALLS WITH SIMPLY BOUNDARY CONDITIONS

SUPPORTED

wall No. Thickness Wythes Frequencies (Hz)

305 6 1 15.31, 22.97, 36.68

12 2 32.15, 48.09, 75.80

6 1 30.78, 69.42 406

12 2 58.63, 132.3

TABLE 2

MAXIMUM STRESS RATIOS OF WALLS WITH SIMPLY SUPPORTED BOUNDARY CONDITIONS

Wall No. Thickness Wythes M/Mxa My/Mya

6 0.422 0.437

12 2 0.143 0.129

0 6 1 0.071 0.170

12 2 0.040 0.097

Note: Subscripts x and y denote stress ratios on horizontal and vertical strips respectively

1-3

'I,ft

TABLE 3

MAXIMUM STRESS RATIOS OF WALLS WITH FIXED BOUNDARY CONDITIONS INCLUDING

OUT-OF-PLANE DRIFT EFFECTS


1-4

Wall' No. Thickness Wythes Mx/Mxa My/mya

305 o 1 0.294 0.335

12 2 0.098 0.220

6 1 0.049 0.246 406

12 2 0.050 0.352

Director of NRR June 30, 1982 Enclosure (2)

2.0 NRC COMMENT

Provide the results of the masonry wall analysis and identify the walls whose calculated stresses exceed the allowables in Table 1 and 2 of Reference 3.

RESPONSE

A summary of all the masonry wall analyses for the Monticello Nuclear Generating Plant is presented here in a tabular form (See "Summary of Wall Analysis"). Based on plate analysis, a summary of the stress levels are also presented here in a tabular form (See "Summary of Masonry Walls Re-evaluation"). The table contains each wall's status in regard to the criteria and the major results, both in-plant and out-of-plane. Where necessary, a brief comment is made.

According to the table ("Summary of Masonry Walls Reevaluation") only Wall Nos. 210, 226 and T324 are overstressed with regard to Tables 1 and 2 of the criteria.

Walls 210, 226 and T324 pass by arching action (See Response No. 8).

2-1

V

SUMARY OF WALL ANALYSIS SA

(WALLS PASSING BY BEAM/PLATrE/ARGBING/ENERGY BALANCE)

WALL BEAM PLATE* ARCH. ENERY NO. ANALY ANALY ANALY. ANALY 110 X. X 112 X X 202 X X 204 X X 206 X 208 X X 209 X X 210 X 211 X X 212 X 216 X X 218 X X 219 X X 221 X X 222 X 223 X X 225 X X 226 X 227 X X 228 X X 229 X X 231 X X 232 X X 237 X X 242 X X 243 X

302 X X 305 X 307 x X 309 X X 310 X X 315 X X 321 X X 340 X X 341 X X 342 X X 343 x X 345 X X 401 x x 402 X X 403 X X 404 X X 405 X X

406 X X_

407 X X

____**

WALL BEAM PLATE* APCH. ENE~RY NO. ANALYI ANALY ANALY. ANALY 408 X X

502 X X

503 X X

504 X X

505 x x

507 X X

511 X X

512 X

516 X

532 X _x

538 X X

543 X

545 X X

546 X X

548 X X

549 X

610 X X 615 X X

616 x

618 X X

C103 X X C105 X x X C107 X X X C109 x X x C1io x x x C112 X X D105 X X

s1ol x x 5104 X X

S202 X X S203 X X S204 X X

S205 X X S207 X X T125 X

T130 X X

T135 X X T311 X X

T321 X X T322 X X T324 X

T330 X X T350 X X T107A x X T109 X X_

* See Summary of Masonry Walls Pe-Fvaluation ** Preliinary Analysis

2-2

0

uluN I ILt LLU - NURTHERN STATES POWER PAGE: 1 C

SUMMARY OF MASONRY WALLS RE-EVALUATION BY: A4rost DATE:rU CHKD: o*0 - DAsT:@

OUT OF PLANE IN PLANE

WALL STATU! SW M M H 0 R I Z 0 NT A L VERTICAL COMMENTS. NR. MW x - T 2 (

or M T R Mxa ya a a a 2 ba ata

m 2 a

113 O.K. SW .010 .021 .010 .031

112 0.K. SW .010 .021 .010 .031

202 O.K. SW .063 .033 .033 .305 .063 .369

204 O.K. SW .059 .128 .038 .032 .063 .096

206 0.K. 5 .074 .703 .043

208 0.K. SW ).119 0.216 0.233 in 2va.u - - -tin(;I. 2.0

- --ost oressu

209 O.K. SW .206 .718 .283 .114 .065 .180 .072 .063

210 N.G. SW.573 3.02R .483 .209 .063 .272

211 O.K. SW .095 .072 .0,66 .479 .066 .344

mie y rum212 0.K. SW .325 .195 .051 0 .330 .330 a

side. 216 0.K. SW .037 .342 .087

218 0.K SW .058 .281 .053

219 0.K. SW .619 .676 .178 .003 .526 .530

221 O.K. SW .089 .329 .053 .032 .066 .098

Fixed by 222 O.K. SW .097 .522 .165 .109 .500 .617 inning the too

223 O.K. SW .135 .554 .308 .077 .326 .603

3 = I1NULL WTIHE

MW = MULTI WYTHE R = REINFORCED -------------------M = MAX. HORIZONTAL SPAN tIT4ENT Mx = MAX. VERTICAL SPAN MOMENT

= MAX. BOUNDARY SHEAR STRESS

= MAX. SHEAR STRESS = MAX. STORY DRIFT INDEX b MAX. BEARING STRESS AGAINST A BOUNDARY t= MAX. BED-JOINT TENSION - VERTICAL LOAD

. = MAX. LOCALIZED SHEAR STRESS

----------- ------------------------------------------------THE SUBSCRIPT "a" INDICATES THE MAXIMUM ALLOWABLE VALUES.

2-3

eI

4

mu m I ILLLLU - N 0 RTHERN STATES P 0 WER

-SUMMARY OF MASONRY WALLS RE-EVALUATION BY: CHKD:

PAGE: 2 ( Jrld~ *DATE :s'

a.. f DATE 3.,


WALL STATU! SW M m H 0 RI Z ONT A L VERTICAL COMMENTS. NR. MW x M_ (2) -(

or - - - (R Mxa Mya a va 'a .cba ata T

(2) :a

225 O.K. SW .162 .216 .048 .078 .066 .144

226 N.G. SW .249 1.301 .163 .033 .063 .096

227 10.K. SW .026 .289 .039

228 0.K. SW .139 .143 .049 .213

229 O.K. SW .203 .376 .244 .033 .066 .093

231 O.K. SW .141 .169 .034

332 O.K. SW .044 .060 .015

237 O.K. SW .022 .169 .143

242 O.K. SW .727 .510 .269 .163 .538 .671

All four 243 O.K. SW 0.348 .800 .. 586 .051 .065 .117 All fred

Just a one 244 O.K. door open

ing

302 0.K. Sw .141 .070 .033 .053 .051 .104

305 O.K. SW .476 .448 .112 .096 .049 .145

307 0.K. SW .239 .140 .041 .031 .049 .080 .001

309 O.K. SW .053 .290 .168 .049 .049 .196

310 0.K. SW .007 .093 .015

SW = SINGLE WYTHE MW = MULTI WYTHE R R REINFORCED

M = MAX. HORIZONTAL SPNi ft-2tENT Mx MAX. VERTICAL SPAN MOMENT

" - MAX. BOUNDARY SHEAR STRESS

v = MAX. SHEAR STRESS c = MAX. STORY DRIFT INDEX 7b= MAX. BEARING STRESS AGAINST A BOUNDARY at= MAX. BED-JOINT TENSION - VERTICAL LOAD

= MAX. LOCALIZED SHEAR STRESS ------- -----------------------------------------------

THE SUBSCRIPT "a" INDICATES THE MAXIMUM ALLOWABLE VALUES.

2-4

R a u n IAUL LU- M iUK IHERN STATES

SUMMARY OF MASONRY WALLS RE-EVALUATION

POWE R PAGE: 3 BY:LJ DATE:L

CHND: .u. ; DATE:L

OUT OF PLANE IN PLANE WALL STATUSW M H 0 R I Z 0 NT A L VERTICAL COMMENTS. NR. MW x ___ ) (2 ) 1

or M at- ( R xa ya a Va ca (2) ba ata

315 O.K. SW .329 133 .079

321 O.K. SW .161 .467 .033 .015 .390 .405

340 O.K. Sw .032 .178 .087 .103 .051 .154

341 O.K. SW .038 .120 .023

342 O.K. Sw .027 .122 .022

343 O.K. SW .03i .132 .029 .163 .049 .212

345 O.K. Sw .057 .132 .023

401 O.K. SW .134 .416 .109

402 O.K. SW' .110 .145 .033

403 O.K. SW .112 .316 .107 .100 .390 490

404 O.K. SW .067 .069 .028

405 O.K. SW .084 .173 .033

406 O.K. SW *08 .178 .033

407 O.K. SW .076 .104 .331

408 0.K. SW .079 .212 .038

502 O.K. sw .027 .188 .046

SW= CTIGL EV JWY 1T 1 lr

MULTI WYTHE REINFORCED

M = MAX. HORIZONTAL SPAN fItMENT M = MAX. VERTICAL SPAN MUIENT Ty = MAX. BOUNOARY SHEAR STRESS

= MAX. = MAX.

b= MAX. -,t= MAX. TL= MAX.

SHEAR STRESS STORY DRIFT INDEX BEARING STRESS AGAINST A BOUNDARY BED-JOINT TENSION - VERTICAL LOAD LOCALIZED SHEAR STRESS


2-5

I'

MW = R =

.

MUNICELLO - NORTHERN

SUMMARY OF MASONRY WALLS

STATES

RE-EVALUATION

POWE R PAGE: 4 BY: /S:DATE:m


WALL STATUNS M M T H 0 R I Z ONTAL VERTICAL COMMENTS. NR. M X 1 ) (2 (1)

R M M T V £ + a R xa ya a a a (2 .ba 'ta

503 O.K. SW .020 .134 .257

504 O.K. SW .051 .101 .020

505 0.K. Sw .058 .093 .053 .014 .286 .300

307 O.K.1 SW .030 .031 .009

511 O.K. SW .053 .381 .066 .003

512 O.K. SW .039 .210 .316

516 O.K. SW .221 .257 .104 .027 .048 .375 .014 .011 - - - - - - .--------

532 0.K. R .574 .451 .883 .006 .048 .053

lU

cracked ---- - ---....--..-...-.......- norizonta

538 0.K. S; .046 .076 .038

543 0.K. St .061 .367 .214

545 O.K. S .034 .047 .042 .251 .286 .538

546 O.K. S .074 .345 .097

548 O.K. S .024 .082 .025

549 O.K. S; .148 .461 .192

610 O.K. Sl .099 .492 .32 .795 .042.837 .072

615 0.K S" .0691 .484 .102

SW = SINGLE WYTHE

MW = MULTI WYTHE R = REINFORCED --------------

M = MAX. HORIZONTAL SPAN MCMENT M= MAX. VERTICAL SPAN MOMENT

= MAX. BOUNDARY SHEAR STRESS

V - MAX. SHEAR STRESS = MAX. STORY DRIFT INDEX

b= MAX. BEARING STRESS AGAINST A BOUNDARY t= MAX. BED-JOINT TENSION - VERTICAL LOAD

S= MAX. LOCALIZED SHEAR STRESS - ---------------------------------------


2-6

e--s -"N r--,% f- - -J - I

M 0 NTICELL O - N 0 RTHERN S TATES


P 0 WER PAGE:

BY :Affi,'J DATE::CHKD: c.0. ; D4TE:3

OUT OF PLANE IN PLANE WALL STATUSW M H 0 R I Z ONT A L VERTICAL COMMENTS.

NR. M - V ( (1) -Eb jt

R xa Mya a a a ( . ba "ta

616 0.K. SW .069 .072 .027 .486 .042 .528 .183

618 0.K. SW .034 .039 .056 .214 .339 .553 .018 .045

SW C103 O.K. R .268 .265 .089 .080 .526 .506 .009 uncracked

sw cracked C105 0.K. R .457 .373 .a56 .504 .066 .570 .034 coth dirn.

C107 .K SWcracked -- R .398 .240 .275 .100 .066 .166 .023 .129 oth dir.

SW both_____ C109 O.K. R .109 .434 .038 .045 .045 .158 uncracked

-s-

Sw cracked C11o O.K. R .839 .506 .199 .075 .045 .120 horizontal SW

C112 O.K. R .291 .306 .076 .057 .063 .121 .026 uncracked

D105 O.K. SW .533L.002 ...211 .068 *localizet

J103 O.K. SW .323 .807 .383 .285 .360 .645 .533 .333

S1ol O.K. SW.406 .834 .087 .291 .526 .817 .023

5104 O.K. Sw' 8 6 .088 .028 .634 .063 .698

5202 O.K. SW.119 .046 .028

S203 O.K. S .496 .872 .166 .055 .526 .381

S204 0. K. SW .203 .155 .069

S205 O.K. S .032 .275 .031

S'a = ')INGLE WYTHE MW = MULTI WYTHE R = REINFORCED ----------------------

Mx= MAX. HORIZONTAL SPANU t4ENT M= MAX. VERTICAL SPAN MSMENT Ty M AX. BOUNOARY SHEAR STRESS

= MAX. SHEAR STRESS E = MAX. STORY DRIFT INDEX b= MAX. BEARING STRESS AGAINST A BOUNDARY t= MAX. BED-JOINT TENSION - VERTICAL LOAD

. MAX. LOCALIZED SHEAR STRESS ----------------- ----------------------------------------------


2-7

e--- r---, r--. r-, rvrl-n --% --- , r

y

NUNILUt L *LU NORTHERN STATES P 0 WER


AGE: 6

DATE :±.' A

DATE :2. .*


WALL STATU! SW H 0 RI Z 0 NTAL VERTICAL COMMENTS. MW x T ) -) NR. v a (1 or -E R xa ya a a a (2) .0ba ta T

-2) .a

S207 O.K. SW .138 .072 .031

All sides T137A O.K. SW .49S .472 .531 .067 oinned.

SW T10.9 O.K. R .199 .677 .056 .203 .360 .563 -- uncracked

without th T123 O.K. SW .302 .533 .357 .059 .360 .419 .033 big oice

SW T130 O.K. R .228 .323 .078 .594 3.394 .0321

T135 O.K. SW .009 .033 .010

w/o pipe T311 O.K. SW .253 .173 .051 .179 .066 .245 ructure

T321 O.K. SW .044 .130 .140 .022 .526 .548 w/o pipe

T322 O.K. SW .u49 .236 .041 .107 .063 .171 upture

3 sides T324 N.G. SW .193 1.48 .229 oinned.

T330 O.K. SW .083 .320 .061

T350 O.K. SW .092 .133 .194 . .068

SW - SINGLE WYTHMW = MULTI WYTHE R - REINFORCED

M x MAX. HORIZONTAL SPNI fnt4ENT M MAX. VERTICAL SPAN MOMENT

2 MAX. BOUNDARY SHEAR STRESS

v = MAX. SHEAR STRESS

vt2

MAX. MAX. MAX. MAX.

-w

STORY DRIFT INDEX BEARING STRESS AGAINST A BOUNDARY BED-JOINT TENSION - VERTICAL LOAD LOCALIZED SHEAR STRESS

THE SUBSCRIPT *a" INDICATES THE MAXIMUM 2-8 ALLOWABLE VALUES.

CHKD: 0.

E

I'


3.0 NRC COMMENT

Indicate whether seismic loading in the vertical direction was considered in the analysis.

RESPONSE

In the Masonry Wall Evaluation, the vertical seismic loading was included in the following manner. Vertical loads and locations of all loads acting on each wall were established. The walls were evaluated for each set of loads both for local effects and for global effects, in accordance with the reevaluation criteria.

The vertical inertial loads of the walls were ignored because in general the maximum acceleration for the vertical motion (the ZPA) was less than 0.2g and did not produce tension in the bed joints or add significantly to the gravitational compression.

The stresses resulting from the analysis for the vertical equipment loads are very low when compared to the allowable values.

3-1


4.0 NRC COMMENT

With respect to frequency shift and out-of-plane drift effects, show that the use of single wythe walls for analyzing multiple wythe walls will yield conservative results.

RESPONSE

Each wythe in a multiwythe wall was assumed to respond as a single wythe wall. Two double wythe walls (Walls No. 305 and 406) were selected to compare the results obtained from the wall acting either as a single or double wythe wall using the re-evaluation criteria. In using the re-evaluation criteria the walls were assumed to have pinned supports at all appropriate boundaries. As a consequence no forces are induced in the wall due to out-ofplane drift. The validity of this assumption is addressed in response Number 6. Some of the results of response Number 6 are included in this response for the purpose of addressing comment Number 4. Wall 305 is 114 inches long, 258 inches high and consists of two wythes of six inch wide units. Wall 406 is 114 inches long, 96 inches high and consists of two wythes of six inch wide units. Each wall was analyzed as both a single and double wythe wall using the same number of nodes, mesh size and boundary conditions. Two boundary conditions were used for each wall; a pinned support on each boundary and a fixed support on each boundary. For the fixed boundary condition the out-of-plane drift effects were included as reported in Response No. 6.

The results of the analyses performed using the simply supported boundary conditions are given in Table 1 and 2. Table 1 compares the frequencies of each wall acting either as a single or double wythe wall. Table 2 compares the maximum stress ratios for each wall acting either as a single or double wythe wall. The values given in Table 2 are based on the procedures given in the re-evaluation criteria. That is the walls are assumed to have simply supported boundary conditions. The results given in Table 3 are extracted from Response Number 6 and provide a comparison of the single or double wythe wall with fixed boundary conditions incorporating the effects of out-of-plane drift.

From the results presented in Table 1 it is clear that the single wythe assumption is conservative with respect to frequency shift. The fundamental or first mode frequency of the double wythe wall is approximately twice that of the single wythe wall. For walls with more than two wythes the shift in frequency would be even greater. The effect of out-of-plane drift depends on how it is incorporated in the analysis of the walls and is further discussed in Response Number 6.

4-1

For the case of simply supported boundary conditions, out-of-plane drift does not induce moments and shear forces in the walls. The maximum stress ratios given in Table 2 indicate that the maximum stresses in the double wythe wall are approximately one-third to one-half of those of the corresponding single wythe wall. For the case of fixed boundary conditions, incorporating out-of-plane drift, the results of Table 3 show that for a relatively low wall (<9')(wall 406) the stress ratios increase. However, these walls in general are not highly stressed and the increased stress ratios are still well below the capacity of the walls. For higher walls (Wall 305), the single wythe assumption is conservative in that the stress ratios decrease significantly when compared to the double wythe wall. This illustrates that the single wythe assumption for fixed boundary conditions is conservative for more highly stressed walls and yields conservative results.

Two walls were selected to demonstrate that the use of the single wythe assumption for multiple wythe walls results in a conservative evaluation with respect to frequency shift and out of plane drift considerations. The results indicate that the frequency of the double wythe walls are almost twice those of the equivalent single wythe wall. Therefore, from frequency shift considerations the use of the single wythe assumption is conservative because the fundamental frequency of each wall was either at the peak of the spectra or off it in the higher frequency range. The impact on out-of-plane considerations depends on how this is incorporated in the analysis. With the method used in the reevaluation criteria no moments or shear forces are induced in the wall due to out-ofplane drift effects and the maximum stress ratios from other out-of-plane forces in the double wythe wall are approximately one-third to one-half of those in .the single wythe wall. If fixed boundary conditions are used and out-of-plane drift effects are included, then the maximum stress ratios in the double wythe walls were less than those in the single wythe wall for higher and more critically stressed walls. For shorter walls, the stress ratios increased when the wall was considered to be double wythe, but the increased stress ratios are still well below the capacity of the walls.

The single wythe assumption is therefore conservative for the procedures specified in the re-evaluation criteria and is reasonably conservative for the procedure of including out-ofplane drift effects specified in Response Number 6.

4-2

I I

TABLE 1

FREQUENCY OF WALLS WITH SIMPLY BOUNDARY CONDITIONS

SUPPORTED

Wall No. Thickness Wythes Frequencies (Hz)

305 6 1 15.31, 22.97, 36.68

12 2 32.15, 48.09, 75.80

6 1 30.78, 69.42 406

12 2 58.63, 132.3

TABLE 2

MAXIMUM STRESS RATIOS OF WALLS WITH SIMPLY SUPPORTED BOUNDARY CONDITIONS

Wall No. Thickness Wythes Mx/Mxa My/My

6 1 0.422 0.437 305

12 2 0.143 0.129

6 1 0.071 0.170 406

12 2 0.040 0.397


4-3

a

TABLE 3

MAXIMUM STRESS RATIOS OF WMLLS WITH FIXED BOUNDARY CONDITIOS INCLUDING

OUT-OF-PLANE DRIFT EFFECTS


4-4

Wall No. Thickness ythes Mx/Mxa My/Mya

6 1 0.294 0.335

12 2 0.098 0.220

6 1 0.049 0.246 406

12 2 0.050 0.352


5.0 NRC COMMENT

With reference to section 6.6 of reference 3, provide justification for not using a factor of 1.5 times the floor acceleration for multiplying the equipment weight as suggested in Section 3.7.2 of the standard review plan.

RESPONSE

The "Standard Review Plan" document was published by the NRC in 1975, whereas the Monticello Plant "Final Safety Analysis Report" was published in July 1969. The "Standard Review Plan" is .not considered applicable to the Monticello Nuclear Generating Plant.

In analyzing each wall, two methods were used -- an equivalent static method and a dynamic modal analysis method.

Prior to any wall analysis all applicable equipment masses and loads (in-plane, out-of-plane and vertical) were established. The loads were calculated by assuming all equipment to be flexible and its mass multiplied by the peak of the applicable floor response spectrum. The wall was then statically analyzed for these loads. However, it should be noted that the equipment was rigidly attached to the walls.

The dynamic analysis procedure was the response spectrum method using the SRSS method for combining.the modal results for the 5 lowest modes. In this method the weight of all equipment attached to the walls was included in the dynamic model in the form of lumped masses at nodes close to or at the actual equipment locations. The addition of these masses produces lower wall frequencies and also increases the out-of-plane differential displacement at the equipment locations, resulting in increased applied moments. The results.of the two analyses (static and dynamic) were then added absolutely,

The "Standard Review Plan" document referenced by the NRC in its response to the "Masonry Wall Evaluation" for the Monticello Nuclear Generating Plant" is not considered applicable because it was published at a later date than the plants' FSAR. However, both a static and dynamic analysis which included equipment forces and weight were performed on each wall with the results added absolutely. This method of analysis is adequate to account for the effect of the rigid equipment attached to a wall.

5-1


6.0 NRC COMMENT

Indicate The boundary conditions used for analyzing the masonry walls and provide justification for those boundary conditions.

RESPONSE

All walls were analyzed in accordance with the procedures given in "Criteria for the Re-evaluation of Concrete Masonry Walls for the Monticello Nuclear Generating Plant." To assess the out-ofplane response of the walls, the boundary conditions at all supports were assumed to be pinned. This assumption was made for the following reason.

1. The stresses resulting from out-of-plane seismic load are conservative.

2. The boundary rotations required for the existence of pinned supports are very small and will exist regardless of what type of fixity is used to prevent it. A field inspection of the walls indicated this was the only reasonable assumption.

In assessing the effect of out-of-plane drift effects on the walls the same assumption of pinned boundary conditions was used for consistency in the analytical procedures. With this assumption no forces are induced in the walls when out-of-plane interstory drift effects are assessed. Two walls (Wall Nos. 305 and 406) were selected to compare the results that would be obtained if fixed rather than simply supported boundary conditions had been assumed. Wall No. 305 is 114 inches long and 258 inches high and Wall No. 406 is 114 inches long and 96 inches high. Each wall is double wythe and was analyzed as a single and double wythe wall with both fixed and simply supported boundary conditions. For the fixed boundary conditions the effects of out-of-plane interstory drift were included in the analysis. The stresses resulting from out-of-plane seismic loads were combined absolutely with those resulting from out-of-plane drift effects. Out-ofplane drift effects were calculated by imposing the Out-ofplane displacement at the top of the wall with the wall fixed against rotation at both the top and the bottom of the wall.

A summary of the maximum stress ratios resulting from the eight analyses performed are given in Table 1. Care must be exercised in evaluating the results because the maximum stresses do not fall in the same region of the wall for the different boundary conditions. In the case of the simply supported boundary conditions the maximu'm stress ratios are towards the center of the wall and for the fixed boundary conditions they are close to or

6-1

The results for Wall 305, which has a height-to-length ratio of 2 to 1 indicate that the maximum stress ratios of the simply supported boundary conditions for a single wythe wall are conserative when compared with those of the fixed boundary conditions that include out-of-plane interstory drift effects. The maximum stress ratio for this wall occurred on a vertical strip and was reduced by almost one-fourth when fixed bundary conditions were used. When the same comparison is made for the double wythe wall, again the maximum stress ratio, which was on a horizontal strip, was reduced by almost one-third. However, the maximum stress ratio on the vertical strip increased from 0.13 to 0.22. In comparing the three analyses; 1) single wythe with fixed boundaries and out-of-plane drift, 2) double wythe with simply supported boundaries and 3) double wythe with fixed boundaries and out-of-plane drift; the maximum stress ratios are all less than the ratios obtained from analyzing the wall with the procedures given in the re-evaluation criteria.

The results for Wall 406, which has a height-to-lenght ratio less than 1, are different from those of wall 305 in that the maximum stress ratios increase on the vertical strip when fixed boundary conditions are imposed. This is attributed to the wall geometry. In general drift induced moments are inversely proportional to the height, whereas the moments due to out-of-plane seismic loads increase in proportion to the square of the height.

Therefore, as the two examples illustrate, there are offsetting effects. Walls of medium to low height (5 to 8 ft.) such as Wall 406, are not highly stressed (30-35% of capacity when pinned boundary conditions are assumed). If fixed boundaries and interstory drifts are considered, then the resulting moments do increase. However, they remain in the region of 40-60% of the wall capacity. For higher walls such as Wall 305 (8 to 20 ft), the moments resulting from pinned boundary conditions are much higher than for low walls (40-100% of the wall capacity). However, when fixed boundary conditions and interstory drift effects are considered in these walls, there is a reduction in the resulting moments.

6-2

CONCLUSIONS

In summary, the procedure used in the re-evaluation criteria assumes the wall have pinned supports at the boundaries. It is our opinion that this is the most realistic representation of field conditions. In addition, the pinning produces a conservative estimate of the stresses resulting from out-of-plane seismic load for higher walls that are significantly stressed.

Two walls were selected to compare the maximum stress ratios obtained from the assumptions used in the re-evaluation criteria with those obtained from using the assumption that the top and bottom boundaries had fixed supports. The stresses obtained for the out-of-plane forces acting on the wall with fixed boundary conditions were added absolutely to those resulting from out-of-plane drift effects.

For the two walls that were analyzed, different results were obtained because of the different heights of the walls selected. For the shorter wall, fixed boundary conditions and interstory drift effects increased the moment on a vertical strip of the wall. However, since these walls in general are not highly stressed, the increased moment was still less than 50% of the capacity. For the higher wall, fixed boundary conditions and interstory drift effects decreased the moment on a vertical strip of the wall. Since these walls are in general the most highly stressed when pinned boundary conditions are assumed, fixed boundary conditions will result in a more conservative assessment.

From the results presented, it is clear that the impact of different boundary condition varies. For shorter walls and, in general, less highly stressed walls fixed boundary conditions will increase the moments on the walls. For taller walls and, in general, more highly stressed walls, fixed boundary conditions will decrease the moments on the walls. Therefore, the boundary conditions used in the reevaluation criteria are conservative for the more highly stressed walls and are the most realistic representation of field conditions.

6-3

TABLE 1

MAXIMUM STRESS RATIOS FOR VARYING BOUNDARY CONDITIONS


* "Stress Ratios from original Analysis"

6-4

Wall No. Thickness (in) Condition Mx/Mxa My/Mya

* 6 Simply Supported 0.422 0.437

305 6 Fixed,Drift 0.294 0.335

12 Simply Supported 0.148 0.129

12 Fixed,Drift 0.098 0.220

* 6 Simply Supported 0.071 0.170

406 6 Fixed,Drift J.049 0.246

12 Simply Supported 0.040 0.097

12 Fixed,Drift 0.050 0.352


7.0 NRC COMMENT

Specify the .number of modes considered in the dynamic analysis and show that the effect of higher modes has been properly accounted for.

RESPONSE

To provide a cross-section of the boundary conditions and openings of the masonry walls at the Monticello Nuclear Generating Plant, the four walls given in Table 1 were selected to document the results of the analyses.

The four walls include three without openings and one with a door opening. One of the walls is not connected at the top boundary but is pinned on the other three boundaries. One wall is pinned on the top, bottom and one side boundary. Two walls are pinned on all four boundaries.

TABLE 1 DESCRIPTION OF WALLS

Wall Wall Boundary Openings Number Thickness Conditions

(in)

315 6 Pinned on 3 sides None (Free on top)

615 8 Pinned on 3 sides None (Free on side)

T107A 6 Pinned on 4 sides None

TI30 8 Pinned on 4 sides Door on one side

All walls were analyzed in accordance with the procedures given in "Criteria for the Re-evaluation of Concrete Masonry Walls for the Monticello Nuclear Generating Plant". Specifically, plate analysis was used to assess the out-of-plane response of all walls. The computer program SAPIV was used to perform a finite element dynamic analysis ultilizing the response spectrum method. The Computech pre-processor program GENIN was used to generate input files for the analyses.

For each wall an eigenanalysis was performed to extract the first five frequencies less than 100Hz and mode shapes and the individual modal responses were combined using the square root of the sum of the squares procedures.

7-1

The SAP output was summarized using the post-processor computer program GENOUT. The computer printout of GENOUT lists seperately the values of the moments and reaction forces for first mode dynamic response, the SRSS of the first five modes of dynamic response and the values from static loads.

The detailed results of the analyses of the four walls are given in Appendices A through D. A summary of the results is given in Table 2 and 3. Table 2 contains a summary of results for walls 315, 615, and T130. Table 3 contains a similar summary of wall TI07A. For each wall an analysis was performed assuming the wall was single wythe with properties as determined in the field. The maximum moment parallel (Mx) and normal (My) to the bed joints and the maximum boundary shear force (F) are given in Tables 2 and 3. In Table 2 the value of each moment or force resulting from the first mode and the SRSS of the first five modes are given. Table 2 also contains the percentage contribution of the first mode to the SRSS of the first five modes for each maximum moment and force quantity.

Table 3 which contains a summary of results for wall T1O7A includes the results from the first mode, the SRSS of the first five modes and the SRSS of the first ten modes. In addition the table also contains the percentage contribution of the first mode to the SRSS of both the first 5 and 10 modes respectively for each maximum moment and force quantity. Also included is the percentage of the SRSS of the first 5 modes to the first 10 modes for each maximum moment and force quantity.

The results of the analyses for walls 315, 615 and T130 presented in Table 2 indicates that the first mode contributes between 91.9% and 99.9% of the SRSS of the first five modes for the maximum moments and boundary forces in the walls. Thus for the opening and boundary conditions of these three walls a first mode analysis would have been sufficient to produce over 90% of the total maximum response quantities. A five mode SRSS analysis is therefore adequate for these three walls.

The results for wall T1O7A presented in Table 3 indicate that the first mode contributes 98.9% of the SRSS of the first 5 modes of response and 98.7% of the SRSS of the first 10 modes of response. The percentage of SRSS of the first 5 modes to the SRSS of the first 10 modes is 99.3% and over for the maximum moments and forces. An SRSS of five modes is almost identical to an SRSS of ten modes.

7-2

CONCLUSIONS

Four walls were selected to provide documentation that the adoption of five (5) modes of response will generally provide over 99% of the total response. The four walls selected, covered the full range of boundary conditions and openings found in the masonry walls at the plant.

The results clearly indicate that five modes of SRSS response provide over 99% of the total response.

As all the masonry walls at the Monticello plant were analyzed using the first five modes of response it is clear that 99% of the total response of all the walls has been included in the analytical results.

7-3

TABLE 2 - SUMMARY OF RESULTS FOR WALLS 315. 615, AND T130

Wall Mxl Mx5 Mxl/Mx5 Myl My5 Myl/My5 Fl FS Fl/F5 Number (Ib-In/in) (Lb-in/in) (%) (Lb-In/In) (Lb-In/in) % (Lb) (Lb) %

315

Solid Block 179.8 180.0 99.9 40.2 42.8 93.9 128.6 131.5 97.8

615k

Solid Block 31.7 34.5 91.9 154.9 155.1 99.9 106.2 109.3 97.2

T130

Partially 125.7 125.8 99.9 100.8 101.0 99.8 92.0 92.5 99.5 Grouted

Notations:

M Maximum moment per linear length F Maximum shear force at boundary x Parallel to the bed joint y : Normal to the bed joint 1 : First mode only 5 : SRSS of the first five modes

A Only four (4) modes were found having frequencies 100Hz.

-4

-Is

I

TABLE 3 - SUMMARY OF RESULTS FOR WALL T107A

Wall Moment Ist SRSS SRSS 1st/5 1st/10 5/10 Number or Force Mode 5 Modes 10 Modes I_ % I .% I %

T107A

Block-Solid Wall

Mx (Lb-in/In) My (Lb-in/In)

F (Lb)

126.3 78.5 85.5

126.4 79.4 86.0

126.6 79.4 86.6

99.9 98.9 99.4

99.8 98.9 98.7,

Notations:(.11

M Maximum moment per lInear length F Maximum shear force at, boundary x Parallel to the bed joint y Normal to the bed joint 1 : First mode only 5 SRSS of the first five modes 10 SRSS of the first ten modes

99.8 100.0

99.3

"10-1.

APPENDIX A

SUMMARY OF COMPUTER RESULTS FOR

WALL 315

7-6

I

--------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I SVEINSSON CHECKED NaRkL 6

SHEET OF

MASONRY WALL ANALYSIS - SAP IV SUMMARY OF .OUTPUT FOR PLATE ANALYSIS

SAP IV EXECUTION RUN

RESPONSE SPECTRUM ANALYSIS, USING 5 MODE SHAPES

* (A) SUMMARY OF INPUT DATA *

MESH LAYOUT

12 NODES 1.00 1.00 1.00 1.00

ALONG X AXIS AT 1.00 1.00 1.00

SPACINGS OF (FEET): 1.00 1.00 ,1.00

10 NODES ALONG Y AXIS AT SPACINGS OF (FEET): 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

SUPPORTS

PINNED SUPPORT PARALLEL GRID 1 FROM I TO 12

PINNED SUPPORT PARALLEL GRID 1 FROM 1 TO 10


TO X ALONG

TO Y ALONG

TO Y ALONG

7-7

*

*

*

*

*

*

*

*

1.00

1.00

-------- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I SVEINSSON CHECKED .E

SREET OF

WALL PROPERTIES

WALL THICKNESS= 5.625 INCHES

STANDARD SOLID BLOCK WALL USING GRADE N MASONRY BLOCK UNITS, AND

TYPE M MORTAR.

COMPRESSIVE STRENGTH FM= 1200 P.S.I AND THE BASIC E VALUE IS 600 TIMES FM, GIVING 960000 P.S.I. THIS IS FACTORED BY 0.9290 TO GIVE THE CORRECT ADJUSTED STIFFNESS BASED ON THE NET I VALUE. FINAL PROPERTIES ARE: MODULUS OF ELASTICITY= 891340. P.S.I POISSONS RATIO = 0.150 WEIGHT DENSITY = 0.0840 LB/CU.IN

7-8

I

.'4.....

-------- COMPUTECH -------

JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I SVEINSSON CHECKED " o. t( E

RESPONSE SPECTRUM

SPECTRUM NAME: MNTNS2

TITLE: NORTH & SOUTH DIRECTION, 2% DAMPING RESPONSE SPECTRUM

SPECTRUM APPLIED IN Z DIRECTION

ACCELERATIONS FACTORED BY 386.0 PERIOD (SECS) ACCEL (0)

0.010 0.220 0.133 0.220 0.139 0.238 0.144 0.254 0.149 0.270 0.189 0.270 0.222 0.540 0.267 0.830 0.322 1.140 0.392 1. 460 0.588 1.460 0.667 1.220 0.741 1.020 0.833 0.800 0.952 0.540 1.075 0.310

--- NO ERROR MESSAGES DETECTED IN SAP OUTPUT

7-9

., . : m ' .I .. -, .1: ., ,: - . - , ,, - . . ... - .

COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I SVEINSSON CHECKED :,3"L o f> (

SHEET OF

SUMMARY OF SAP OUTPUT *

NUMBER OF NODAL POINTS = 121 NUMBER OF ELEMENT TYPES = 2

NUMBER OF LOAD CASES = 0 NUMBER OF FREQUENCIES = 5 ANALYSIS CODE (NDYN) = 3

EQ.0, STATIC EQ.1, MODAL EXTRACTION EQ.2, FORCED RESPONSE EQ.3, RESPONSE SPECTRUM EQ.4, DIRECT INTEGRATION EQ.5, FREQUENCY RESPONSE

SOLUTION MODE (MODEX) = 0 EQ.0, EXECUTION EG.1, DATA CHECK

NUMBER OF SUBSPACE ITERATION VECTORS (NAD) = 0 EQUATIONS PER BLOCK = 0 TAPE10 SAVE FLAG (N1OSV) = 0 GRAVITATIONAL CONSTANT = 386.00 TOTAL BLANK COMMON (MTOT)=25000

STRUCTURE PLOTTING IS REQUESTED REQUIRED BLANK COMMON FOR THIS STEP= 1211

TOTAL NUMBER OF EQUATIONS = 360

BANDWIDTH - 36

NUMBER OF EQUATIONS IN A BLOCK = 328 NUMBER OF BLOCKS = 2

7-10

-------- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I SVEIp4SSON CHECKED : t 4 o-v 1

SHEET OF

PRINT OF FREQUENCIES

CIRCULAR FREQUENCY (RAD/SEC) 0.7838E 02 0.2189E 03 0.2591E 03 0.4190E 03 0.5164E 03

FREQUENCY (CYCLES/SEC) 0.1247E 02 0.3484E 02 0.4124E 02 0.6669E 02 0.8219E 02.

0. 0. 0. 0. 0.

PERIOD (SEC)

8016E-01 2870E-01 2425E-01 1500E-01 1217E-0 1

TOLERANCE

0.3790E-13 0.1943E-13 0. 7628E-12 0.1608E-06 0.8140E-06

MODAL PARTICIPATION FACTORS

X-DIRECTION 0.OOOOE 00 0.OOOOE 00

.0.0000E 00 0.0000E 00 0.0OE 00

Y-DIRECTION 0.OO0E 00 0.OOOOE 00 0.OO0E 00 0.0OE 00 0.OOOOE 00

Z-DIRECTION 0.3290E 01

-0.1223E 01 0.2603E-0 0. 5661E-05 -0.6678E 00

7-11

MODE NUMBER

1

3 4 5

MODE 1 2 3 4 5

--------- COMPUTECH --------JOB NO. JOB NAME BUILDING WALL I.D. DATE BY CHECKED

: J542 :MONTICELLO :REACTOR :315 NRC-STUDY :04/02/82 :BJORN I SVEINSSON

ET OF

PLATE ELEMENTS -- MAXIMUM MOMENTS

X-MOMENTS (LB-IN/IN)

DYNAMIC MODE1 S.R.S.S.

179.8 172. 5 172.5 165.7 159.0 159.0 151.3 151.3 150.0 144.0

180.0 172.7 172.7 165.8 159.1 159. 1 151.4 151.4 150.0 144.0

STATIC COMBINED (ABSOLUTE)

0.0000 0. 0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. 0000 0.0000 0.0000

180.0 172.7 172.7 165.8 159. 1 159. 1 151.4 151.4 150.0 144.0

Y-MOMENTS (LB-IN/IN)


40. 18 37.85 38. 56 38. 56 36.32 36.32 37.96 32.32 36.44 36.44

42. 81 42.55 41.07 41.07 40.32 40.82 38.97 38.87 37.39 37.39


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

42.81 42.55 41.07 41.07 40.82 40.82 38.97 38.87 37.39 37.39

7-12

ELEMENT NUMBER

54 45 63 53 44 62 36 72 52 43

ELEMENT NUMBER

51 50 42 60 41 59 52 49 43 61

-------- COMPUTECH-------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :315 NRC-STUDY DATE :04/02/82 BY :BJORN I .VEINSSON CHECKED : A4L ou IV

SHEET OF

BOUNDARY ELEMENTS --- MAXIMUM FORCES

EACTION FORCES (LB)

DYNAMIC S. R. .S.

154.4 12. 14 23.97 33.25 40.97 46. 65 50.07 50.87 47.20 131. 5 15.77 31.05 43.04 51.69 56.44 56.44 51.89 43.04 31.05 15.,77 154.4 12. 14 23.97 33.25 40.97 46.65 50.07 50. 87 47.20 131. 5

1579.


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

0.0000

154.4 12. 14 23.97 33.25 40.97 46.65 50.07 50.87 47.20 131. 5 15.77 31.05 43.04 51.89 56.44 56.44 51.89 43.04 31.05 15.77 1,54.4 12. 14 23.97 33.25 40.97 46.65 50.07 50.87 47.20 131. 5

1578.

7-13

ELEMENT NUMBER

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 29 29 30

NODE NUMBER

1 2 3 4 5 6 7 8 9

10 11 21 31 41 51 61 71 81 91

101 111 112 113 114 115 116 117 118 119 120

MODE 1

-153.0 10.49 21.33 30.62 38.98 45.50 49.62 50.78 47. 15 128.6 15. 10 29.70 41. 19 49.64 54.00 54.00 49.64 41. 18 29.70 15. 10

-153.0 10.49 21.33 30.62 36.98 45.50 49.62 50. 78 47. 15 128. 6

919.4TOTAL:

i, . . .. . .

APPENDIX B


WALL 615

7-14

--------- COMPUTECH-------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :kAL o ( 0 (

SHEET OF

*

*

*

*

MASONRY WALL ANALYSIS - SAP IV SUMMARY OF OUTPUT FOR PLATE ANALYSIS

*

*

*

*




MESH LAYOUT

9 NODES ALONG X AXIS AT SPACINGS OF (FEET): 1.00 1.00 1.00 1.00 1.00 1.00 1.00

9 NODES ALONG Y AXIS AT SPACINGS OF (FEET): 1.00 1.00 1.00 1.00 1.00 1.00 1.00

1.00

1. 50

SUPPORTS


PINNED SUPPORT PARALLEL 'GRID 9 FROM 1 TO 9


TO X ALONG

TO X ALONG

TO Y ALONG

7-15

-------- COMPUTECH--------JOB NO. JOB NAME BUILDING WALL I.D. DATE BY CHECKED

: J542 :MONTICELLO :REACTOR :615 NRC-STUDY :04/02/82 :BJORN INGI SVEINSSON

SHEET OF

WALL PROPERTIES


STANDARD SOLID BLOCK WALL USING GRADE U MASONRY BLOCK UNITS, AND

TYPE M MORTAR.

COMPRESSIVE STRENGTH FM= 1200 P.S.I AND THE BASIC E VALUE IS 800 TIMES FM, GIVING 960000 P.S.I. THIS IS FACTORED BY 0.9290 TO GIVE THE CORRECT ADJUSTED STIFFNESS BASED ON THE NET I VALUE. FINAL PROPERTIES ARE: MODULUS OF ELASTICITY= 891840. P.S.I POISSONS RATIO = 0.150 WEIGHT DENSITY '0.0840 LB/CU.IN

7-16

-------- COMPUTECH -------

JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY. DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED %kk 44(-tI

SHEE OF

RESPONSE SPECTRUM




ACCELERATIONS FACTORED BY 509.5 PERIOD (SECS) ACCEL (0.)

0.010 0.220 0.133 0. 220 0.139 0.238 0.144 0.254 0.149 0.270 0.189 0.270 0.222 0.540 0.267 0.330 0.322 1.140 0.392 1.460 0.586 1.460 0.667 1.220 0.741 1.020 0.833 0.800 0.952 0.540 1.075 0.310


7-17

--------- COMPUTECH-------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED : ML, b v I.

SHEET F

SUMMARY OF SAP OUTPUT

NUMBER OF NODAL POINTS = 82 NUMBER OF ELEMENT TYPES = 2 NUMBER OF LOAD CASES = 0 NUMBER OF FREQUENCIES = . 5 ANALYSIS CODE (NDYN) = 3

EQ.0, STATIC EQ.1, MODAL EXTRACTION EQ.2, FORCED RESPONSE EQ.3, RESPONSE SPECTRUM EG.4, DIRECT INTEGRATION EQ.5, FREQUENCY RESPONSE

SOLUTION MODE (MODEX) = 0 EQ.0, EXECUTION EQ.1, DATA CHECK



TOTAL NUMBER OF EQUATIONS = 243 BANDWI.DTH = 33 NUMBER OF EQUATIONS IN A BLOCK = 243 NUMBER OF BLOCKS = 1

7-18

COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :11M . ou(Y 1,

SHEET OF


CIRCULAR FREQUENCY

(RAD/SEC) 0.1237E 03 0.3047E 03 0.4241E 03 0.6287E 03

FREQUENCY (CYCLES/SEC) 0.1969E 02 0.4849E 02 0. 6750E 02 0.1001E 03

0. 0. 0. 0.

PERIOD (SEC)

5077E-0 1 2062E-01 1482E-01 9994E-02


X-DIRECTION 0.OOOOE 00 0.OO0E 00 0.0OE 00 0.0000E 00

Y-DIRECTION 0.OO0E 00 0.OOOOE 00 0.0000E 00 0.OOOOE 00

Z-DIRECTION -0.2703E 01

0.9882E 00 0. 5918E-01

-0.1602E-01

7-19

MODE NUMBER

1 2 3 4

MODE 1 2 3 4

1

-------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY DATE :04/02/92 BY :BJORN INGI SVEINSSON CHECKED :. tifL( .

SHEET OF

PLATE ELEMENTS - MAXIMUM MOMENTS



-31.69 -30.56 -27.79 -31. 75 -26.80 -30.60 -28.56 -25.04 -28.64 -21.39

34. 48 33.24 32.97 32.47 31.79 31.30 31.08 29.73 29.29 27.69


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

34.48 33.24 32.97 32.47 31.79 31.30 31.08 29.73 29.29 27.69


DYNAMIC MODEl S.R.S.S.

-154.9 -149.2 -141.2 -139.8 -136. 1 -127.5 -125.7 -123.7 -121.2 -113.5

155. 1 149.5 141. 3 140. 1 136.1 127.5 125.8 123.9 121.2 113.5


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

155.1 149.5 141.3 140. 1 136.1 127.5 125.8 123.9 121.2 113.5

7-20

ELEMENT NUMBER

37 29 36 38 23 30 45 44 46 35

ELEMENT NUMBER

40 32 39 48 31. 47 38 24 30 46

------ COMPUTECH

JOB NO. :J542 'JOB NAME :MONTICELLO BUILDING :REACTOR WALL I.D. :615 NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED, : Z \ s -y b

SHEET OF


EACTION FORCES (LB)

ELEMENT NODE NUMBER NUMBER MODE1

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 19 19 20 21 22 23 24 25

1 2 ' 3 4 5 6 78 9

10 19 28 37 46 55 64 73 74 75 76 77 78 79 8o 81

TOTAL:

117.3 -12.69 -25. 69 -36.62 -46.09 -52.71 -55.80 -52.78 -104.4 -18.86 -36.06 -47. 58 -52.92 -52.12 -39.52 -35.30

114.9 -12.79 -25. 11 -36.26 -45.59 -51.74 -56.42 -48.11 -106. 2

-619.2

DYNAMIC S. R. S.S.

118. 9 14.62 28. 75 39.49 47. 88 53. 32 55.84 52.86 107.6 19.76 37. 81 49.89 55.51 54.65 41.61 37.03 116.5 14.70 26.09 39.08 47.34 52.35 56.46 48. 16 109.3

1327.


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. 0000. 0.0000 0.0000 0.0000 0.0000

0.0000

118.9 14.62 28.75 39.49 47.88 53.32 55.84 52.86 107. 6 19.76 37.81 49.89 55. 51 54.65 41.61 37.03 116.5 14.70 28. 09 39.08 47.34 52.35 56.46 48. 16 109.3

1327.

7-21

------------------------------- ------------------------

(

0APPENDIX C

SUMMARY OF COMPUTERRESULTS FOR

WALL T1O7A

7-22

-------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED o

OF

*MASONRY WALL ANALYSIS - SAP IV SUMMARY OF OUTPUT FOR PLATE ANALYSIS

****** *********I++++E+XEC++T+ION++RUN



****** ************* ********4****

* (A) SUMMARY OF INPUT DATA * ***** **************************

MESH LAYOUT.

11 NODES ALONG X 1.30 1.30 1.30 1.30 1.30

13 NODES 1.50 1.50 1.50 1.50

ALONG Y 1. 50 1.50

AXIS AT SPACINGS OF (FEET): 1.30 1.30 1.30 1.30

AXIS AT 1. 50 1. 50

SPACINGS OF (FEET): 1.50 1.50 1.50

SUPPORTS




PINNED SUPPORT PARALLEL G.RID 11 FROM I TO 13

TO X ALONG

TO X ALONG

TO Y ALONG

TO Y ALONG

7-23

*

)

1. 30

1. 50

-a

- - COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T1O7A PINNED ALL DATE :04/02/e2 BY :BJORN INGI SVEINSSON CHECKED :o\ML ok(V I

SHEET OF

WALL PROPERTIES



TYPE M MORTAR.

COMPRESSIVE STRENGTH FM= 1200 P.S.I AND THE BASIC E VALUE IS 800 TIMES FM, GIVING 960000 P.S.I. THIS IS FACTORED BY 0.9290 TO GIVE THE CORRECT ADJUSTED STIFFNESS BASED ON THE NET I VALUE. FINAL PROPERTIES ARE: MODULUS OF ELASTICITY= 891840. P.S.I POISSONS RATIO 0.150 WEIGHT DENSITY = ' 0.0840 LB/CU.IN

7-24

--------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED : tU 4,(.

SHEET 0

RESPONSE SPECTRUM




ACCELERATIONS FACTORED BY 264.0 PERIOD (SECS) ACCEL (G.)

0.010 0.220 0.133 0.220 0.139 0.236 0.144 0.254 0.149 0.270 0.189 0.270 ' 0.222 0.540 0.267 0.1830 0.322 1.140 0.392 1.460 0.588 1.460 0.667 1.220 0.741 1.020 0.833 0.800 0.952 0.540 1.075 0.310


7-25

--------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED NW\ 0t "

SHEET OF

* * **** *** *** ********++ * ee*s

SUMMARY OF SAP OUTPUT *

NUMBER OF NODAL POINTS = 144 NUMBER OF ELEMENT TYPES = 2 NUMBER OF LOAD CASES = 0 NUMBER OF FREQUENCIES = 5 ANALYSIS CODE (NDYN) = 3

EQ. 0. STATIC EQ.1, MODAL EXTRACTION EG.2, FORCED RESPONSE EQ.3, RESPONSE SPECTRUM EG.4, DIRECT INTEGRATION EQ.5, FREQUENCY RESPONSE

SOLUTION MODE (MODEX) = 0 EQ.0, EXECUTION EQ.1, DATA CHECK



TOTAL NUMBER OF EQUATIONS = 429 BANDWIDTH = 39 . NUMBER OF EQUATIONS IN A BLOCK = 304 NUMBER OF BLOCKS = 2

7-26

--- COMPUTECH --------JOB NO. JOB NAME BUILDING WALL I.D. DATE BY CHECKED

:J542 :MONTICELLO :TURBINE :T107A PINNED ALL :04/02/82 :BJORN INGI SVEINSSON

SHEET OF




0. 0. 0. 0. 0.

PERIOD (SEC)

9663E-01 4749E-01 3243E-01 2563E-01 2400E-01

TOLERANCE

0. 0. 0. 0. 0.

4130E-13 8912E-12 3319E-07 1901E-06 9271E-05


X-DIRECTION 0.OOOOE 00 0.O0OE 00 0.O0OE 00 0.OO0E 00 0.OOOOE 00

Y-DIRECTION 0.0OE 00 0.OOOOE 00, 0.OOOOE 00 0.OOOOE 00 0.0OE 00

Z-DIRECTION 0.5133E 01 0.1583E-07

-0.1151E-04 0.1632E 01

-0.5767E-03

7-27

MODE NUMBER

1 2 3 4 5

MODE 1 2 3 4 5

--- COMPUTECH -------JOB NO. JOB NAME BUILDING WALL I.D. DATE BY CHECKED

: J542 :MONTICELLO :TURBINE :T107A PINNED ALL :04/02/92 :BJORN INGI SVEINSSON :*(40 IT" L SHEET OF

PLATE ELEMENTS -- MAXIMUM MOMENTS ------------------------------


DYNAMIC MODEl S.R.S.S.

126.3 126.3 126.3 126.3 117.7 117.7 117.7 117.7 113.9 113.9 113.9 113.9

126.4 126.4 126.4 126.4 117.7 117.7 117.7 117.7 114.0 114.0 114.0 114.0


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. OOGO 0.0000 0.0000 0.0000 0.0000

126.4 126.4 126.4 126.4 117.7 117.7 117.7 117.7 114.0 114.0 114.0 114.0


DYNAMIC MODE1 S. R. S. S.

78. 78. 79. 78. 73. 73. 73. 73. 70. 70. 70. 70.

50 50 50 50 15 15 15 15 82 82 82, 82

79.36 79.36 79.36 79.36 73.31 73.31 73.31 73.31 71. 59 71.59 71. 59 71. 59


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

79.36 79.36 79.36 79.36 73.31 73.31 73.31 73.31 71. 59 71..59 71. 59 71.59

7-28

S

ELEMENT NUMBER

55 56 65 66 45 46 75 76 54 57 64 67

ELEMENT NUMBER

55 56 65 66 45 46 75 76 54 57 64 67

-Th

-----------------------------------------------

COMPUTECH ------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED : ZK, aWO11-t

SHEET OF

BOUNDARY ELEMENTS -- MAXIMUM FORCES

EACTION FORCES (LB)

NODE NUMBER MODEl

1 2 3 4 5 6 7 8 9

10 11 12 22 23 33 34 44 45 55 56 66 67 77 78 88 89 99

100 110 111 121 122 132 133

-146.0 19.61 38.33 52.26 61.57 64.70 61.57 52.26 38.33 19.61

-146.0 21.76 21.76 43.01 43.01 60.39 60.39 74.04 74.04 82.57 82.57 85.49 85.49 82.57 82. 57 74.04 74.04 60.39 60.39 43.01 43.01 21.76 21.76

-146.0

DYNAMIC S. R. S. S.

146.3 19. 92 38.94 53.09 62. 55 65.73 62.55 53.09 38.94 19. 92 146.3 22.76 22.76 44. 10 44. 10 60.77 60.77 74.04 74.04 82.85 62.85 86.03 86.03 82.85 82.85 74.04 74.04 60.77 60.77 44. 10 44. 10 22.76

22.76 146.3


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. 0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. 0000

146.3 19.92 38.94 53.09 62.55 65.73 62. 55 53.09 38.94 19.92 146.3 22.76 22.76 44. 10 44. 10 60.77 60.77 74.04 74.04 82.85 82. 85 86.03 86.03 82.85 82.85 74.04 74.04 60.77 60.77 44. 10 44. 10 22.76 22.76 146.3

7-29

ELEMENT NUMBER

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 19 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/62 BY :BJORN INGI SVEINSSON CHECKED :T k- 64 (

SHEET OF

19.92 38.94 53.09 62.55 65.73 62. 55 53.09 38.94 19.92 146.3

.2725.

0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.10000 0.0000

0.0000

19.92 38.94 53.09 62. 55 65.73 62.55 53.09 38.94 19.92 146.3

2725.

-b

07-30

35 36 37 38 39 40 41 42 43 44

134 135 136 137 138 139 140 141 142 143

19.61 38.33 52.26 61.57 64.70 61.57 52.26 38.33 19.61

-146.0

TOTAL: 1531.

--------- COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :buf vtayl

SHEET OF

******

*

*

MASONRY WALL ANALYSIS - SAP IV SUMMARY OF OUTPUT FOR PLATE ANALYSIS

********************++++++



* **S*M*********** * **NPUT +D

* (A) SUMMARY OF INPUT DATA * ******************* ***+++++++++

*

*

*

MESH LAYOUT

11 NODES 1.30 1.30 1.30 1.30

13 NODES 1.50 1.50 1.50 1.50

ALONG X AXIS AT SPACINGS OF (FEET): 1.30 1.30 1.30 1.30 1.30

ALONG Y 1.50 1. 50

AXIS AT 1. 50 1. 50


1.30

1. 50

SUPPORTS





TO X ALONG

TO X ALONG

TO Y ALONG

TO Y ALONG

7-31

t.

- COMPUTECH-------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T1O7A PINNED ALL DATE :04/02/82. BY :BJORN INGI SVEINSSON CHECKED

I(

WALL PROPERTIES.



TYPE M MORTAR.

COMPRESSIVE STRENGTH FM= 1200 P.S.I AND THE BASIC E VALUE IS 800 TIMES FM, GIVING 960000 P.S.I. THIS IS FACTORED BY 0.9290 TO GIVE THE CORRECT ADJUSTED STIFFNESS BASED ON THE NET I VALUE. FINAL PROPERTIES ARE: MODULUS OF ELASTICITY= 891840. P.S.I POISSONS RATIO = 0.150 WEIGHT DENSITY = . 0.0840 LB/CU.IN

7-32

- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED AL bY A ,

S EET OF

RESPONSE SPECTRUM




ACCELERATIONS FACTORED SY 264.0 PERIOD (SECS) ACCEL (G.)

0.010 0.220 0.133 0.220 0.139 0.238 0.144 0.254 0. 149 0. 270 0.189 0.270 0.222 0.540 0.267 0.830 0.322 1.140 0.392 1.460 0.588 1.460 0.667 1.220 0.741 1.020 0.833 0.600 0.952 0.540 1.075 0.310

--- NO ERROR MESSAGES DETECTED IN SAP OUTPUT ---

7-33

- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED : \ bv(v( .

SHEET OF

SUMMARY OF SAP OUTPUT,

NUMBER OF NODAL POINTS = 144 NUMBER OF ELEMENT TYPES 2 NUMBER OF LOAD CASES 0 0 NUMBER OF FREQUENCIES = .10 ANALYSIS CODE (NDYN) = 3

EG.0, STATIC EQ.1, MODAL EXTRACTION EG.2, FORCED RESPONSE EQ.3, RESPONSE SPECTRUM EQ.4, DIRECT INTEGRATION EQ.5, FREQUENCY RESPONSE

SOLUTION MODE (MODEX) = EG.0, EXECUTION EQ.1, DATA CHECK

NUMBER OF SUBSPACE ITERATION VECTORS (NAD) = 0 EQUATIONS PER BLOCK = 0 TAPE10 SAVE FLAG (NIOSV) = 0 GRAVITATIONAL CONSTANT = 396.00 TOTAL BLANK COMMON (MTOT)=25000


TOTAL NUMBER OF EQUATIONS = 429 BANDWIDTH = 39

NUMBER OF EQUATIONS IN A BLOCK = 258 NUMBER OF BLOCKS = 2

7-34

------- COMPUTECH -------JOB NO. :J542 JOB NAME .MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :j ., QV7vt4aQ

SHEET OF


CIRCULAR FREQUENCY (RAD/SEC) 0.6502E 02 0.1323E 03 0.1937E 03 0.2451E 03 0.2618E 03 0.3759E 03 0.4045E 03 0.4097E 03 0.4788E 03 0.5369E 03

FREQUENCY (CYCLES/SEC) 0.1035E 02 0.2106E 02 0.3083E 02 0.3901E 02 0.4166E 02. 0.5982E 02 0.6437E 02 0.6521E 02 0.7620E 02 0.8545E 02

0. 0. 0. 0. 0. 0. 0. 0. 0. 0.

PERIOD (SEC)

9663E-01 4749E-01 3243E-01 2563E-01 2400E-01 1672E-01 1553E-01 1534E-01 1312E-01 1170E-01

TOLERANCE

0.1377E-13 0.1330E-13 0.2481E-13 0.0000E 00 0.1359E-13 0.2055E-10 0.2596E-11 0.3769E-08 0.1321E-06 0.9670E-06


X-DIRECTION 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OO0E 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OO0E 00

Y-DIRECTION O.OO0E 00 0.OO0E 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.0000E 00 0.OOOOE 00 0.OOOOE 00 0.0000E 00

Z-DIRECTION 0.5133E 01

-0.9807E-11 0.1569E-10

-0.1632E 01 -0.1436E-11 0.2261E-07 0.1078E-08 0.1596E 01

-0.2680E-05 0. 2941E-05

7-35

MODE NUMBER

1 2 3 4 5 6 7 8 9 10

MODE 1 2 3 4 5 6 7 a 9 10

JOB NO. JOB NAME BUILDING WALL I.D. DATE BY CHECKED

- COMPUTECH -------:J542 :MONTICELLO :TURBINE :T107A PINNED ALL :04/02/82 :BJORN INGI SVEINSSON

SHEET OF




126.3 126.3 126.3 126.3117.7 117.7 117.7 117.7 113.9 113.9 113.9 113.9

126.6 126.6 126.6 126.6 117.9 117.9 117.9 117.9 114.0 114.0 114.0 114.0


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

126.6 126.6 126.6 126.6 117.9 117.9 117.9. 117.9 114.0 114.0 114.0 114.0


DYNAMIC MODEl S.R.S.8.

79. 50 78. 50 78. 50 78. 50 73. 15 73. 15 73. 15 73. 15 70.82 70.82 70.82 70.82

79.37 79. 37 79.37 79.37 73.32 73.32 73.32 73.32 71. 59 71. 59 71. 59 71.59


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

79.37 79.37 79.37 79.37 73.32 73.32 73.32 73.32 71. 59 71.59 71.59 71. 59

'I

7-36

ELEMENT NUMBER

55 56 65 66 45 46 75 76 54 57 64 67

ELEMENT NUMBER

55 56 65 66 45 46 75 76 54 57 64 67

-------- COMPUTECH ------JOB NO. :J542 JOB NAME :.MONTICELLO BUILDING :TURBINE WALL I.D. :T107A PINNED ALL DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED 's %1 o 'tj

SHEET OF


EACTION FORCES (LB)

NODE NUMBER MODEl

1 2 3 4 5 6 7 8 9 10 11 12 22 23 33 34 44 45 55 56 66 67 77 78 88 89 99

100 110 111 121 122 132 133

-146.0 19.61 38.33 52.26 61.57 64.70 61. 57 52.26 38.33 19. 61

-146.0 21.76 21.76 43.01 43.01 60.39 60.39 74.04 74.04 82.57 82. 57 85.49 85.49 82. 57 82.57 74.04 74.04 60.39 60.39 43.01 43.01 21.76. 21.76

-146.0

DYNAMIC S. R. S.S.

146.3 20. 14 39. 11 53. 10 62. 58 65.83 62. 58 53. 10 39. 11 20. 14 146.3 22.89 22.89 44.36 44.36 61. 14 61. 14 74.51 74. 51 83.37 83. 37 86. 56 86. 56 83.37 83.37 74.51 74. 51 61. 14 61. 14 44.36 44.36 22.39 22.89 146.3


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

146.3 20. 14 39. 11 53. 10 62. 58 65.83 62. 58 53. 10 39. 11 20. 14 146.3 22.89 22.89 44.36 44.36 61. 14 61. 14 74. 51 74. 51 83.37 63. 37 86. 56 86. 56 83.37 83.37 74.51 74.51 61. 14 61. 14 44.36 44.36 22. 89 22.69 146.3

7-37

ELEMENT NUMBER

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 16 19 20 21 22 23 24 25 26 27 23 29 30 31 32 33 34


20. 14 39.11 53.10 62. 58 65.83 62. 58 53. 10 39. 11 20. tA 146.3

2735.

0. 0. 0. 0. 0. 0. 0. 0. 0. 0.

COMPUTECH -

: J542 :MONTICELLO :TURBINE :T107A PINNED ALL :04/02/82 :BJORN INGI SVEINSSON

0000 0000 0000 0000 0000 0000 0000 0000 0000 0000

0.0000

20. 14 39. 11 53. 10 62. 58 65.83 62.58 53. 10 39. 11 20. 14 146.3

2735.

7-38

35 36 37 38 39 40 41 42 43 44

134 135 136 137 138 139 140 141 142 143

19.61 38.33 52.26 61.57 64.70 61.57 52.26 38.33 19.61

-146.0

TOTAL: 1531.

APPENDIX D


WALL T130

7-39

-------- COMPUTECH -------

JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :S4 \(i 1

SHEET OF

MASONRY WALL ANALYSIS - SAP IV * SUMMARY OF OUTPUT FOR PLATE ANALYSIS *

*




MESH LAYOUT

12 NODES 1.25 1.25 1.00 0.75

12 NODES 1.25 1.25 1.25 1.25

ALONG X AXIS AT 1.25 1.25 0.75

ALONG Y AXIS AT 1.25 1.25 1.50 '



WITH OPENINGS XL XR 7 10

SUPPORTS

ENCLOSED BY FOLLOWING GRIDS: YL YU

1 7

PINNED SUPPORT PARALLEL TO X ALONG GRID 1 FROM 1 TO.12

PINNED SUPPORT PARALLEL TO X ALONG GRID 12 FROM 1 TO 12

PINNED SUPPORT PARALLEL TO Y ALONG GRID 1 FROM 1 TO 12

PINNED SUPPORT PARALLEL TO Y ALONG GRID 12 FROM 1 TO 12

7-40

0

*

1.25

1.25

COMPUTECH -------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY DATE :04/02/e2 BY :BJORN INGI SVEINSSON CHECKED S

WALL PROPERTIES-


NON-STANDARD WALL. INPUT PROPERTIES ARE: MODULUS OF ELASTICITY= 723200. P.S.I POISSONS RATIO = 0.150 WEIGHT DENSITY = 0.0619 LB/CU.-IN

7-41

-------- COMPUTECH -------

JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED : t (Wv V ,

SHEET OF

RESPONSE SPECTRUM

SPECTRUM NAME: MNTEW2

TITLE: EAST & WEST DIRECTION, 2% DAMPING RESPONSE SPECTRUM


ACCELERATIONS FACTORED BY 266.7 PERIOD (SECS) ACCEL (G)

0.010 0.220 0.133 0.220 0.139 0.239 0.145 0.259 0.152 0.280 0.192 0.280 .

0.222 0.550 0.267 0. 880 0.322 1.230 0.374 1.510 0.556 1.510 0.606 1.350 0.667 1.180 0.741 0.980 0.833 0.770 0.952 0.520 1.080 0.300

--- NO ERROR MESSAGES DETECTED IN SAP OUTPUT ---

7-42

-------- COMPUTECH ------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY, DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED :,Skt oQ 7vj ,

SHEET F

SUMMARY OF SAP OUTPUT * '

** ** **** * ***** ** *** ** ********** *

NUMBER OF NODAL POINTS = 145 NUMBER OF ELEMENT TYPES = 2 NUMBER OF LOAD CASES 0 NUMBER OF FREQUENCIES = 5 ANALYSIS CODE (NDYN) = 3

EQ. 0, STATIC EQ.1, MODAL EXTRACTION EQ.2, FORCED RESPONSE EQ.3, RESPONSE SPECTRUM EQ.4, DIRECT INTEGRATION EQ.5, FREQUENCY RESPONSE

SOLUTION MODE (MODEX) = 0 EQ.0. EXECUTION EG.1, DATA CHECK

NUMBER OF SUBSPACE ITERATION VECTORS (NAD) = 0 EQUATIONS PER BLOCK = 0 TAPE10 SAVE FLAG (NIOSV) = 0 GRAVITATIONAL CONSTANT = 386.00 TOTAL BLANK COMMON (MTOT)=25000


TOTAL NUMBER OF EQUATIONS = 396 BANDWIDTH 42 NUMBER OF EQUATIONS IN A BLOCK = 284 NUMBER OF BLOCKS = 2

7-43


------- COMPUTECH -: J542 :MONTICELLO :TURBINE :T130 - NRC-STUDY :04/02/82 :BJORN INGI SVEINSSON

SHEET




0. 0. 0. 0. 0.

PERIOD (SEC)

5670E-01 2445E-01 1904E-01 1271E-01 1219E-01

TOLERANCE

0. 0. 0. 0. 0.

7583E-13 1410E-13 1095E-11 2123E-07 1132E-05


X-DIRECTION 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00

Y-DIRECTION 0.OO0E 00 0.OOOOE 00. 0.OOOOE 00 0.OOOOE 00 0.OOOOE 00

Z-DIRECTION 0.3962E 01 -0.4121E 00 -0.3017E 00 -0.7904E 00 -0.1087E 01

7-44

MODE NUMBER

-2 3 4 5

MODE 1 2 3 4 5


------ COMPUTECH --------:J542 :MONTICELLO :TURBINE :T130 - NRC-STUDY :04/02/82 :BJORN INGI SVEINSSON

SHEET OF




125.7 89. 16 84. 15 82. 62' 77. 28 73.87 73.92 68.40 67.39 64.56 63.56 62.95

125.8 89.20 84.23 82.66 77.31 74. 11 73.96 68. 43 67.45 64.63 63.64 63.03


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

125.8 89.20 94.23 82. 66 77.31 74.11 73.96 68.43 67.45 64.63 63.64 63.03


ELEMENTNUMBER MODE1

50 39 61 49 38 28 60 48 59 27 37 71

DYNAMIC

100.8 96.83 83. 11 83.41 80.65 79. 25 77.42 70.01 68.23 66.47 65.44 64.9 8

S. R. S. .

101.0 97.06 83.61 83. 58 80.83 79.85 77.76 70. 16 68.49 67.03 65.65 65. 12


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0. 0000

101.0 97.06 83. 6.1 83.58 80.183 79.85 77.76 70. 16 68.49 67.03 65.65 65. 12

7-45

ELEMENT NUMBER

73 72 84 83 71 74 82 60 70 59 94 81

-----------------------------------------------

-------- COMPUTECH-------JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY DATE :04/02/82 BY :BJORN INGI SVEINSSON CHECKED ;-1\,j P4 ,(

SHEET OF


EACTION FORCES (LB)

NODE NUMBER MODE1

1 2 3 4 5 6 7 8 9

10 11 12 13 24 25 36 37 48 49 60 61 72 73 84 85 96 97 108 109 120 121 132 133 134

-128. 1 15.24 29.48 38.91 43.33 39.54 84.85

0.0000 0.0000 91.96

0.3394 -91.84

16.83 1.614 32.97 2.965 45.20 5.233 53.88 5. 514 58.02 47.89 57.63 67. 16 52.88 53.31 44.38 40.60 32.31 30.54 19.75 19.27

-117.8 16.35

DYNAMIC S. R. S.S.

128.4 16.05 30. 68 39.94 44.07 40. 19 95. 54

0.0000 0.0000 92.47

0.4888 92.31 17.62 2.317 34.07 4.369 46.05 7.090 54.39 7.378 58. 33 48. 17 57.85 67.41 53.05 53. 56 44.60 41.31 32.69 31.65 20. 16 20. 45 117.9 16. 53


0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000. 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

128.4 16.05 30.68 39.94 44.07 40. 19 65. 54

0.0000 0.0000 92.47

0.4888 92.31 17.62 2.317 34.07 4.389 46.05 7.090 54.39 7.378 58.:33 48. 17 57.85 67.41 53.05 53. 56 44.60 41.31 32.69 31.65 20. 16 20.45 117.9 16. 53

7-46

ELEMENT NUMBER

1 2 3 4 5 6 7 6 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

0

-------------------------------- -----------------------

-------- COMPUTECH JOB NO. :J542 JOB NAME :MONTICELLO BUILDING :TURBINE WALL I.D. :T130 - NRC-STUDY DATE :04/02/92 BY :BJORN INGI SVEINSSON CHECKED v\ o0y

SHEET 0l

32.34 44.54 53. 08 56.69 54.29 47.22 31.69 13. 18 6.433 123. 0

1870.

0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

0.0000

32.34 44.54 53.08 56.69 54.29 47.22 31.69 13. 13 6.433 123.0

1870.

7-47

35 36 37 36 39 40 41 42 43 44

135 136 137 136 139 140 141 142 143 144

32.02 44.14 52.63 56. 15 53.60 46. 36 30.89 12.72 6.210

-122.6

922.3TOTAL:


8.0 NRC COMMENT

In reference 3, the licensee indicates that the "Arching Theory" has been used to qualify some of the masonry walls. The NRC does not accept the application of the arching theory to masonry walls in Nuclear Power Plants in the absence of conclusive evidence to justify this application. Provide conclusive justification for use of the Arching Theory.

RESPONSE

Blast tests on unreinforced masonry walls have shown that when these walls are confined between relatively rigid edge supports that can develop large in-plane clamping forces, they can develop a substantially higher capacity to resisting out-of-plane loads than would otherwise be predicted on the basis of conventional methods (References 1, 2, and 3). The development of this additional capacity is due to the mechanism of "arching action" i.e., the action of the wall butting against theedge supports and forming a threehinged arch after cracking in flexure occurs.

The basic behavior of arching action of an unreinforced masonry wall subject to out-of-plane loads can be illustrated by Figure

1. Assuming that gross sliding of.the wall does not occur initially under the load, the wall deflects under flexural action as the load increases. A flexural crack develops at the mid-span of the wall where the maximum bending moment is present. At this point the wall segments on both sides of the crack tend to rotate about the edge supports as the wall deflects under the load.

Because of the finite thickness of the wall, this rotation results in the wall jamming against the edge supports, and inducing axial compression in the wall. The wall resists the out-of-plane load by the mechanism of a three-hinged arch. The load resistance continues until the maximum resistance is reached due to gross instability (snap-through of a shallow arch), local crushing of masonry at the hinges, or yielding of the edge supports.

8-1

The load resistance by arching action as described above depends entirely on the magnitude of axial compression that can be developed as the result of the wall deflection. Its effectiveness is greatly influenced by the following parameters:

(a) The initial depth to span ratio of the arch which is governed by the wall thickness-to-height ratio;

(b) In-plane axial stiffness and capacity of the wall;

(c) Compressive stiffness and capacity of the edge supports in the axial direction of the wall;

(d) Initial gap between the edge support and the wall.

The existence of an initial gap has a profound effect on the mechanism of arching as depicted in Figure 2. As shown in this figure, two types of arching mechanism exist depending upon the existence of lateral support for the wall at the gap. If the wall has adequate lateral supports at the gap as shown in Figure 2-A, the arching mechanism takes a symmetrical form similar to that of the wall without a gap, except that the effect of an initial gap must be considered.

For the case that lateral supports, for the wall at the gap, are not present, the arching mechanism will take a "Non-symmetrical form" as shown in Figure 2-B. This results in an initial arch depth only one half as big as that for the same wall with the symmetrical arching mechanism. The reduction in the initial arch depth greatly decreases the effectiveness of arching action. Therefore, in the application of the archining theory only symmetrical arching for a wall without a gap or a gapped wall with adequate lateral supports is allowed. The non-symmetrical arching for a gapped wall is not permitted.

8-2

ANALYSIS OF SYMMETRICAL ARCHING ACTION

Mode and Assumptions

In order to analyze the capacity by arching action of a one-way unreinforced masonry wall, the model shown in Figure 3 is used. The model has the following assumptions.

(a) The wall geometry is symmetrical about the center span where a flexural crack will form immediately upon the application of a uniform lateral (out-of-plane) load on the wall:

(b) The wall is simple-supported laterally and has adequate lateral supports that prevent sliding of the wall under the application of lateral loads. For a gapped wall, this implies that lateral supports exist for the wall at the gap;

(c) The edge supports of the wall have a compressive elastic support spring stiffness coefficient K in the axial direction of the wall.

(d) The axial force P in the wall acts at the centroid of the compressive stress block or the contact areas between the wall and the edge supports and between the wall segments on either side of the center span flexural crack. The compressive stress block is assumed to be triangular when the block is in the elastic deformation range and rectangular in the plastic (crushing) deformation range. Crushing of the block is assumed to occur when the extreme fiber contact stress reaches the compressive strength of the block. (e) The lateral load on the wall is a uniform inertia load of magnitude q = q(t).

8-3

Formulations

Referring to Figure 3, the equilibrium, compatibility and constitutive

relations for a one-half span wall segment can be developed as follows:

a. Equilibrium Equation (Figure 3)

=L P ( Co +E1 8 (1)

Where

q = uniform lateral (out-of-plane) load on the wall

L = span of the wall

P = axial force in the wall

Eo 1 = locations of the axial forces (the locations of centroid of

the contact stress block) at the center span and edge

support, respectively, relative to the wall mid-surface.

A = lateral (out-of-plane) displacement of the wall at the center span.

Due to symmetry, identical contact stress blocks will develop at the center

span and the edge support of the wall; thereby:

To 1

This assumption is reasonable since the axial contact force P is identical

for all contact areas.

b. Compatibility Equation

Referring to Figures 4 and 5, the compatibility of rigid body displacement

requires that the chord length AA' joining the neutral axis (zero

compressive strain) locations at the center span and the edge support,

before and after the rigid body displacement be equal, i.e.:

[(1-2k)t] + 1( 2 = [(1-2kit - A_ + L 2r (3)

8-4

Where

t = thickness of the wall

kt = distance from the neutral axis to the extreme compressive fiber,

i.e. length of compressive stress block

C = rigid body axial displacement at the support

Since C/L<<1, Equation (3) can be reduced to:

A2 - 2(1-2k)tA + CL = 0 (4)

The rigid body axial displacement 4 at each support must match the sum

of axial displacements resulting from the wall's axial and bending de

formations, the initial gap, and the axial displacement of the edge

support. This condition can be expressed as:

C Us + Ua + Ub + CO; (See figure 5) (5) 2

where

Us = axial displacement of the edge support due to axial force P

Ua = axial shortening of the wall segment due to compressive force P

Ub = axial :shortening of the wall at the edge support due to bending

rotation of the wall under the combined action of axial force

P and the lateral load q.

Co = initial gap

8-5

c. Constitutive Relations '

The following constitutive relationships result from the consideration of

the wall segment as a beam model:

Ua = P(L/2) = PL (6) E(A/2) EA

Ub = PC L(1-2k)t - qL3.(1-2k)t (7) 4El 48El

where

E = Young's Modulus of the wall

A = Axial cross-sectional area of the wall

I = Bending moment of inertia of the wall

Note that one-half of the axial area of the wall is assumed effective

in Equation (6). This is to account for the local deformation effect

of the wall at the contact regions.

The axial displacement Us of the edge support with stiffness coefficient

K due to P can be written as:

Us = ( 8) K

3. Solution

Combining Equations (1), (2), (4), and (5) through (8) leads to:

A2 - 2A + Y = 0 (9)

Where

= (1-2K)t 1 - PL2 12El (10)

'= PL2 1 + EA - AC (1-2k)t + o

8-6

Equations (1) and (9) can be used to solve for A and q giving the load dis

placement relationship between q and A provided that( is known. The magni

tude of 5 can be determined from the assumption of stress blocks in the

elastic and plastic ranges.

a. Elastic Range

The assumption of triangular compressive stress block in the elastic range

leads to the following relation for ( for a solid wall:

= t - kt

(12)

For a rectangular hollow concrete block wall, E can be determined, as

shown in Figure 9, by the following:

= t - kt + 2kt - 1 C9 3

23 -_ _ (13)

1c2 1-C1C92

where C1, C2, and C3 are as defined in Figure 9.

The solution in the elastic range is valid until the extreme fiber

compressive--stress at the contact areas reaches the compressive strength

of the block, fm*

b. Plastic Range

Beyond the elastic range, 'the assumption of rectangular compressive stress

block leads to the following relation for ( for a solid wall:

= t - kt (14) 2 -2

8-7

For a rectangular hollow concrete block wall,Ccan be determined by the

following equation as shown in Figure 10:

where C'1 and C'2 are as defined in Figure 10.

tkt + kt 1 - C-' (C'2 )2

(15) 1 - C'1 C'2

8-8

4. Correlation with Tests

Research has been performed to document the arching phenomena. See figure 6 for references. Additional references can be found within each reference.

The conditions necessary for arching action are present in Nuclear Power Plant Facilities. In general many masonry walls are in fill panels surrounded by very rigid concrete and steel structures. Rigid boundaries provide favorable conditions for arching action to occur as shown by the tests performed in the references.

In order to check the accuracy of the Arching Theory developed previously, the results of the MIT tests on the static behavior of solid brick beams under lateral loads as reported in Reference 2 are used for correlation with the analysis. Correlation Analyses are made for two series of beam tests, namely the series of 3 beams 8-1, 8-2, 8-3, and the series of 12-1, 12-2, 12-3, as identified in Reference 2, Table II. All test beams are constucted of rectangular solid bricks. The first series of 3 beams have a span of 3 ft. The second series of 3 beams have a span of 12 ft. All beams were tested under fixed end conditions. Therefore, initial gaps were not present and a rigid edge support condition is considered to be reasonable.

Analyses for the two series of beam tests are based on the following parameters:

Series of 8-1, 8-2, 8-3 Series of 12-1, 12-2, 12-3

b =12 in b =12 in

b = 8 in t = 8 in

L = 96 in L = 144 in

f', = 900 psi f'm = 684 psi

E = 1000 ksi E = 1000 ksi

, o = 0 = 0

K = co K =

8-9

The values of f'm were obtained by averaging the test values of 3 beams in each series respectively. The results of the analysis are correlated with the test results as shown in Figure 7 for the series of 8-1, 8-2, and 8-3, and in Figure 8 for the series of 12-1, 12-2, 12-3. In each case, 3 load-displacement points were calculated, the first points correspond to the end of elastic response, and the other two points are the solutions in the plastic range.

From the comparison shown in Figure 7 and 8 it can be seen that the analysis results compare favorably with the test results.

APPLICATION TO OUT-OF-PLANE SEISMIC RESPONSE OF WALLS

The out-of-plane seismic response of a one-way unreinforced masonry wall can be analysed utilizing the load-displacement relationship by the arching action. Considering the cyclic nature of the seismic inertial load, only limited local crushing of the block at the contact regions should be permitted for conservatism. Therefore the maximum allowable out-of-plane uniform load gall is limited to 1/3 of the maximum load as predicted by the arching analysis.

It should be noted that a reduction of the allowable uniform load to 1/3 of the maximum load generally brings the allowable capacity of the wall to within the value of the elastic response (See Figure 7, 8 and 9). The reduction factor of 3 is consistent with the factor of safety that is generally used in the masonry industry in developing the code allowables.

In summary, the arching theory used for analyzing the out-of-plane response of unreinforced masonry walls has been developed on the basis of proven behavior observed in tests and with close correlation with available test results. The correlations show that the theory is reasonably accurate in predicting the maximum capacity of the walls. In application of the theory, conservative allowables are derived using a factor of safety of 3 which is consistent with the margin of safety of industry codes. Therefore, the application of arching action to analyse unreinforced walls subjected to an out-of-plane seismic inertial load is consistent with the industry code practice.

8-10

Out of Plane Load...q . q/(t)

L

Fiqure 1 Arching action illustrated initial gap do not exist

oo I

P

WI' .~

V.

pInitial Ga

Initial Position

Position at

Final

contact

Pos

(A)

' Support

I

Initial Ga

Initial Position

Position at con

Final Position-

Figure 3 Arching Action Illustrated Initial Gap Exist At Top Of Wall

(A) Lateral Support Provided At Top (B) No Lateral Supports

00.

(B)

". 1. , -; .

I. --

q - q(t)

a a 0 0

Arching Model

L/2

I.I

L/2

III

S.

I

Figure 3

Initial Positfor

N.A.A

Fgr e .

of Cho

Compat1bi1lt R Body Displacement Ofi R19ido t lustrated

8-14I

0

tion Of Cho

C'j

Position of Wall Segment after Rigid Body Displacement

Final Position of Wall Segment After Elastic Body Displacement

eutral Axis

Figure 5 Axial Com ression of Spring and Axial Shortening of wall lustrated

D. REFERENCES

(1) Gabrielson, B.L. and K. Kaplan. "Arching in Masonry Walls Subjected to Out-of Plane Forces", Earthquake Resistanc.e of Masonry Construction, National Work Shop, NBS 016, 1978, pp. 283-313.

(2) McDowell, E.L., K.E. McKee, and E.' Savin," Arching Action Theory of Masonry Walls". Journal of the Structural Division, ASCE, Vol. 82, No. ST2., March 1956, Paper No. 915.

(3) McKee, K.E. and E. Sevin, "Design of Masonry Walls For Blast Loading", Journal of the Structural Division, ASCE Transactions, Proceeding paper 1511.January 1958.

Fqcure (4

8-16

Bechtel Arching Theory MIT DATA ARCHING THEORY (By A CE)

0.4 0.6 0.8 MIDSPAN DEFLECTION (IN.)

(0) 8 ft Span

Correlation of MIT Arching Test Data With Theory for Eight Feet Solid Brick Wall

8-17

16

.o

0

OI

Figure 7

-*- Bechtel Arching Theory

MIT DATA ARCHING THEORY (By SCE)

0.4 0.6 0.8 1.0 MIDSPAN DEFLECTION (IN.)

(b) 12 ft Span

Figure 6. Correlation of MIT Arching Test Data With Theory for Twelve Feet Solid Brick Wall

8-18

0

5

a O

0

C = L. I fl o * < 2CL for .. .

C3

f

Cp

Figure Hollow Block Wall Elastic Stress Block

8-19

t

I b_ C I L 2 s

' L t for t < kt; 2 kt '

C = 11 - 71 3t'

b

Figure /o Hollow Block Wall Plastic Stress Block

8-20

t

P

0

f


9.0 NRC COMMENT

Provide information on construction practices and availability of relevent quality assurance/quality control records to justify the use of allowable stresses applicable to the special inspection category.

RESPONSE

Contruction Practices

Blocks were installed plumb, level and true to line and all corners and angles square as is evident in Figures 1, 2, 3, and 4. Levels and string lines to maintain accuracy were used as is especially evident in Figures 3 and 4.

Units were solidly bedded to mortar with vertical and horizontal joints being aproximately 3/8" inch thick. Joints were straight, clean and uniform in thickness. This is evident in Figures 4 and 5. Exposed masonry surfaces were free of mortar stain, concrete scum and grout stains. Any holes were filled. Any defective mortar joints were rejointed. This is evident in the finished walls in Figures 6 and 8 and in the first finished courses shown in Figure 3.

No exterior masonry was erected when the temperature was below 400F. Interior walls were allowed to be erected when the outside temperature was below 400F, provided that an ambient temperature above 40OF was maintained during erection and for a period of not less than 48 hours after erection was stopped.

Construction was performed in the enclosed portions of the buildings and was protected from .temperature extremes. Please note the shirt sleeved condition of men working in 'Figures 1, 3, 4, 5, and 7.

Blocks were neatly stacked and readily available for use at the jobsite. This is evident in Figures 4, 8, 9 and 10.

Care was taken so as not to chip, crack or damage masonry units when handling them during construction. Figure 9 shows a masons strap used to ease handling and placement of masonry units.

In general, only sufficient mortar was prepared in batches, of the volume, that would be used before initial set took

9-1

To aid in the alignment of.additional courses of masonry, the first course was placed to help align the remaining courses. See Figure 11.

As part of the construction practice, general inspection was performed by Bechtel field engineering personnel to ensure compliance with the requirements of the specification. See Figure 12 (Standard Concrete Block Masonry Report Work from December 16, 1968 to January 18, 1969).

Inspection

Adequate inspection and monitoring of the work was performed. Construction photographs were taken to record and monitor the construction of the walls. See Figures. 1 through 11. Construction/Engineering work releases were used to control the work performed by the subcontractor. Inspection reports were made during the construction of the walls. Block certification.reports were submitted by suppliers. See Figure 12 ("Standard Concrete Block Masonry Report of Work from December 16, 1968 to January 19, 1969). See Figures 13 and 14 (Concrete Block Release #43 and #44). See Figures 15 and 16 (Twin City Testing and Engineering Laboratory Inc. test results dated December 15, 1969 and January 12, 1970). See Figure 17 (Bechtel field engineers memo dated January 14, 1969). See Typical Inspection Report dated February 3, 1969, Figure 18.

Adequate construction methods were used to provide a reliable and durable wall that conforms to the drawings and specifications. Adequate inspection and monitoring was performed to justify the allowable mortar and masonry strengths used in the reevaluation.

9-2

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9-4

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10.0 NRC COMMENT

Provide values of allowable shear stress for flexural members for the case in which reinforcement takes the shear.

RESPONSE

The 1979 Uniform Building Code (UC-Table 24-H) and the ACI-531 Table 10-1 provide guidelines for maximum allowable working stresses in masonry. The values provided for shear are identical to those provided for 'service load shear values in the "Criteria for the Reevaluation of Concrete Masonry Walls - Monticello Nuclear Generating Plant." Missing from Table 1 of the reevaluation criteria are values for shear in flexural members where reinforcement takes the shear. For consistency the values from code s for this category have been added to the criteria. Table 1 of the criteria thus modified is accompanying this report.I

10-1

Table 1: Allowable Stresses in Reinforced Masonry

Allowable Maximum Allowable Maximum Description (psD (psD (psD (psD

Comoressive

Axial' 0.22f'm 1000 0.44f'm 2000 Flexural 0.33f'm 1200 0.85f'm 2400

Bearing

On full area 0.25f'm 900 0.62f'm 1800 On one-third area or less 0.375f'm 1200 0.95f'm 2400

Shear

Masonry Takes Shear

Flexural Members 1.1 v7m 50 1.7 /Fm 75

Shear Walls 3 .

M/Vd > 1 0.9 / 34 1.5 ;Cm 56 M/Vd 7 0 2.0 V f74 3.4vf'm 123

Reinforcement Takes Shear

Flexural Members 3.0 / 150 4.5 225

Shear Walls

M/Vd > 1 1.5/T-m 75 2.5 ifm 125 M/Vd 0 2.01f'm 120 3.4 /if'm 180

Reinforcement

Bond

Plain Bars 60 80 Deformed Bars 140 186

Tension

Grade 40 20.000 0.9Fy Grade 60 24.000 0.9Fy Joint Wire .SFv or 0.9Fv

30.000

Compression 0.4Fy 0.9Fy

10-2


11.0 NRC COMMENT

With reference to Table 1 and 2 in reference 3, justify use of the following increase factors for factored loads (the increase factors allowed in the SEB Criteria (4) are shown in parentheses).

Shear in Flexural Members

Shear Wall (Masonry Takes Shear)

1.5 (1.3)

1.67-1.7 (1.3)

Shear Wall (Reinfocement Takes Shear) 1.67-1.7 (1.5)

Bond 1.3

Tension Normal To Bed Joint

Tension Parallel to Bed Joint

1.67(1.3)

1.67(1.5)

RESPONSE

The following is a justification of the factors used:

11-1

TABLE OF CONTENTS

INTRODUCTION .......................... . . . .. 1

2 SHEAR IN FLEXURAL MEMBERS...................... 2

2.1 Test Programs To Date........................ 2 2.2 Evaluation of the Test Results . . . . . . . . . . . . . . . . . . . . 2 2.3 Conclusions.........................2 2.3 Co enc io s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.4 References........................................3

3 SHEAR WALLS ............................. ... 4

3.1 Overview of Test Program ........ ...................... 4 3.1.1 Applicability of Test Results . . . . . . . . . . . . . . . . . . 4

3.2 Evaluation of Test Data. . ................... 6 3.2.1 Shear Stresses for OBE and SSE Events . . . . . . . . . . 6 3.2.2 Statistical Analysis of the Data.......... . . . . . 7 3.2.3 Discussion of Results .... .. ... ... .. . . . . . .. 13

3.3 CONCLUSIONS.. ....................... 13 3.4 REFERENCES ............................ 14

4 BOND...................................19

5 TENSION NORMAL TO BED JOINT................ . . .. 20

5.1 Overview of Test Programs . . . . . . . . . . . . . . . . . . . . . 20 5.1.1 Applicability of Test Results . . . .. . . . . . . . . . . . 20

5.2 Evaluation of the Test Results . . . . . . . . . . . . . . . . . . . 22 5.2.1 Description of Statistical Analyses . . . . . . . . . . . . . . 22 5.2.2 Results of Statistical Analyses . . . . . . . . . . . . . . . . 24

5.2.2.1 Sample Statistics . . . . . . . . . . . . . . . . . . . . 24 5.2.2.2 Confidence Intervals on the Population Mean . . . . . 25 5.2.2.3 Discussion of Normal vs. Gamma Distribution . . . . . 25 5.2.2.4 95% Confidence Intervals . . . ... . . . . . . . . . . . 26 5.2.2.5 Safety Factors Based on the Mean . . . . . . . . . . 26 5.2.2.6 Probabilities of Exceedance . . . . . . . . . . . . . . 27

5.2.3 DISCUSSION OF RESULTS . . . . . . . . . . . . . . . . . . 27 5.3 CONCLUSIONS ................. ....... ............ 28 5.4 REFERENCES .......... ........................ 29

(1)

6 TENSION PARALLEL TO THE BED JOINT . .

6.1 AVAILABLE TEST RESULTS . . . .. . . . . .. . . . . . . 6.1.1 -APPLICABILITY OF TEST RESULTS . . . . . . . . . .

6.2 EVALUATION OF MONOTONIC TEST RESULTS . . . . . . . 6.2.1 Description of Statistical Analyses . . . . . . . . . . 6.2.2 Results of Statistical Analyses . . . . . . . . . . . .

6.2.2.1 Sample Statistics ................ 6.2.2.2 Confidence Intervals on the Population Mean -. 6.2.2.3 Discussion of Normal vs. Gamma Distribution 6.2.2.4 95% Confidence Intervals............ 6.2.2.5 Safety Factors Based on the Mean . . . . . . 6.2.2.6 Probabilities of Exceedance . . . . . . . . . .

6.2.3 DISCUSSION OF RESULTS . . . . . . . . . . . . . . 6.3 CONCLUSIONS ..................... **....... 6.4 REFERENCES. ... * * ** I* ......

(11)

. . . 33

. . . . 33

. . . . 33

. . . . 33

. . . . 34 . . . . 35 . . . . 35

. 35 . . . . 36 . . . . 37 . . . . 37

38 . . . . 39 . . . . 39 . . . . 40

k.,

1 INTRODUCTION

The Nuclear Regulatory Commission (NRC) staff on March 2. 1982 reviewed the submittal on IE Bulletin 80-11. *Masonry Wall Evaluation. for the Monticello Nuclear Generating Plant. Item 11 resulting from the review required the licensee to justify use of the following increase factors for factored loads:

a. Shear In Flexural Members 1.5 b. Shear Wall 1.67-1.7 C. Bond 1.3 d. Tension Normal to Bed Joint 1.67 e. Tension Parallel to Bed Joint 1.67

The justification is provided In the following Sections 2. 3. 4. 5 and 6 for Items a. b. c. d and e. respectively.

0

1

2 SHEAR IN FLEXURAL MEMBERS

The following Is a justification for using a stress increase factor of 1.5 for shear In flexural members for factored loads.

2.1 Test Programs To Date

References 1. 2. 3 and 4 contain results of several tests on concrete masonry beams and lintels failing both In flexure and shear. These test results form the basis of the flexural shear evaluation that follows below.

2.2 Evaluation of the Test Results

In the summary table. Table 2-1. the major results of the tests that exhibited a shear failure are listed. These are the two ratios listed. Ratio 1 and Ratio 2, which are the ultimate shear forces divided by the allowable shears for unfactored and factored loads respectively. The criteria specified flexural stresses are 1.1/Fm with a maximum of 50 psi for the unfactored loads (OBE) and 1.7w/fThi with a maximum of 75 psi for the factored loads (SSE). For each of the tests the maximum stress governed.

The weighted averages and ranges of the available test results are 5.85 with a range from 2.72 to 9.20 for the unfactored loads and 3.90 with a range from 1.81 to 6.13 for the factored loads.

2.3 Conclusions

The average factor of safety for the flexural shear stress for factored loads is 3.90 using a stress increase factor of 1.50. This margin of safety for a total of 21 tests Is deemed to be very satisfactory and fully justifies the use of the 1.5 stress Increase factor.

2

TABLE 2-1

2.4 References

1. Mayrose. Herman E., Tests of Reinforced Concrete Block Masonry Lintels.' National Concrete Masonry Association. 1954.

2. Saemann. J.C.. "Investigation of the Structural Properties of Reinforced Concrete Masonry. NCMA. 1955.

3. Mackintosh. Albyn. *Tests of Reinforced Concrete Masonry Beams. 1956.

4. 'Tests Prove Concrete Masonry Beams Effective.' Concrete Masonry Age. December. 1956.

3

RATIO 1: RATIO 2* Number

of Ultimate Ultimate Tests Allowable Shear (50 psD Allowable UIL Shear (75 psD Ref.

1 5.96 / 3.97 1 2 7.83 5.22 2 3 9.20 6.13 1 1 2.89 1.93 3. 4 2 4.65 3.10 1 3 4.90 3.27 1 3 4.19 2.79 1 1 2.72 . 1.81 3. 4 1 6.75 4.50 1 2 6.50 4.33 2 2 5.90 3.93 2

Total: 21 Weighed Avg.: 5.85 Weighted Avg.: 3.90

3 SHEAR WALLS

The following Is a justification for using stress increase factors for shear walls of 1.67-1.7 for factored loads.

3.1 Overview of Test Program

The results from an ongoing masonry test program being performed at the Earthquake Engineering Research Center. University of California. Berkeley. are used In this section to evaluate the in-plane shear strength of masonry piers. The tests basically consist of subjecting masonry piers to an in-plane cyclic shear load with the test setup shown in Figure 3-1. The results of the research have been reported in references 1. 2. 3. 4 and 5. The piers are tested by applying three cycles of load at a specified amplitude. The amplitude is gradually increased as the test progresses until the pier is unable to resist any further load. Each test was photographed after each set of three cycles of load, thereby providing detailed records of the crack pattern.

To date over ninety piers have been tested using three different types of materials. Thirty-five of the piers tested were constructed from hollow concrete block masonry units and of these six had a height-to-width ratio of 0.5. fifteen hid a height-to-width ratio of 1. and fourteen had a height-to-width ratio of 2. The piers were constructed from either 6-inch or 8-inch wide hollow concrete block units using Type M mortar. The strength of prisms constructed from the same materials that were used in the piers varied from 1350 to 3500 psi.

The information obtained from each test consisted of a plot of the force-deflection relationship for each cycle of loading. From this set of curves several parameters could be determined, including:

(a) Ultimate Strength

(b) Stiffness Degradation

(c) Hysteresis Envelope

(d) Deflection of Pier at each Loading Stage

3.1.1 Applicability of Test Results

The information obtained from the Berkeley test program is valuable In evaluating the in-plane shear performance of masonry piers subjected to seismic loads. A discussion on the applicablity of the test results is discussed separately with respect to the following variables -- loading. size of test specimen, boundary conditions, material strengths and reinforcement.

4

A. Loading

Although an earthquake type time history was not used as the input motion to the test specimen, the gradually increasing, amplitude dependent, cyclic loading was typical of that used in many other test programs on reinforced concrete and steel structural elements. The most important aspect of loading required to evaluate the seismic performance of structural elements is that the loading be cyclic or reversed. Other variables such as the rate of loading. sequence of loads. etc., may be important but are secondary in comparison to the requirement that the loading be cyclic.

B. Size of Test Specimen

The size of the test specimen used In the Berkeley test program was limited by the capacity of the actuators. The piers with a height-to-width ratio of 0.5 were 3 ft. 4 inches high and 6 ft. 8 inches long, the 1 to 1 piers were 4 ft. 8 inches high and 4 ft. long whereas the 2 to 1 piers were 5 ft. 4 inches high by 2 ft. 8 inches long. Although these sizes are generaly smaller than the walls found in the Monticello Nuclear Generating Plant. it Is assumed that they are of adequate size to represent the behavior of larger sized walls with the same aspect or height-to-width ratio. It should be noted that no experimental evidence is available to validate or refute this assumption.

The aspect or height-to-width ratios Included in the test program cover all the walls at the Monticello Nuclear Generating Plant.

C. Boundary Conditions

The boundary conditions of the piers tested In the Berkeley program were such that moment fixity was forced at both the top and bottom of the piers with no constraints on the vertical edges. Although this set of boundary conditions is different from that of most of the walls at the Monticello Nuclear Generating Plant. It is believed that if the walls at the plant are confined either on three or four sides or at the top and bottom. then the performance of the walls will be similar to those tested in the Berkeley program. Confinement should be provided by either walls or columns capable. of resisting the loads Imposed by the concrete block walls.

5

D. Material Strenaths

The assumed compressive strength frm of the walls at the Monticello Nuclear Generating Plant was 1200 psi. This Is lower than the range of 1350-3500 psi of the prism strength of the piers included in the Berkeley test program. however. It is our opinion that the actual insitu f'm of the walls is within the range tested in the Berkeley program.

E. Reinforcement

The majority of the walls at Monticello Nuclear Generating Plant are unreinforced whereas all the piers of the Berkeley test program were reinforced. It is our belief that provided the walls at the Monticello Nuclear Generating Plant are confined on three or four sides or at the top and bottom. then cracks in the unreinforced wall will occur at similar strain levels to the piers tested.

3.2 Evaluation of Test Data

The data from thirty-three tests performed on hollow concrete block piers was evaluated on the basis of shear stress. in-plane loads on walls result from both imposed deflections and shear forces Imposed by piping and other equipment.

3.2.1 Shear Stresses for OBE and SSE Events

The test results from the Berkeley program were evaluated to determine In-plane shear stresses appropriate for OBE and SSE events. The evaluation was performed so that the function of a wall would not be impaired while it was resisting out-of-plane loads. During each pier test. photographs were taken after each set of three cycles of load at a specified amplitude. These photographs in conjunction with the hysteresis envelopes developed for each test were used to determine the appropriate state of cracking due to in-plane loads that could be tolerated from an OBE and SSE event. For an OBE event, the loading stage at which initial visible cracks occurred was used. For an SSE event, additional cracking was permitted. however, the loading stage was prior to any significant diagonal cracking. Obviously the evaluation for an SSE event required judgment and photographs shown In Figures 3-2. 3-3. and 3-4 show the typical state of cracking used for both an OBE and SSE event for piers with height-to-width ratios of 0.5. 1. and 2. respectively. At each appropriate level of cracking the corresponding shear stress and displacement were determined. The shear stresses obtained were statistically evaluated and these results are presented in the following subsection.

6

3.2.2 Statistical Analysis of the Data

A total of 33 tests were used to evaluate the shear stress for both OBE and SSE events. These were divided as follows:

Masonry Takes the Shear:

M/Vd M/Vd MNd

0.25 0.5 1.0

1 4 7

Test Tests Tests

Reinforcement Takes the Shear:

M/Vd M/Vd M/Vd

0.25 0.5 1.0

5 10

6

Tests Tests

Tests

it is recognized that the number of tests is small in most these tests are the only ones available.

To begin with, all the test data was normalized by dividing values by the square root of the appropriate f'm. This constant. C. of the equation:

cases. but

the stress leaves the

vC = Cm

This constant Is the subject of the statistical analysis that follows herein.

From this data. the following parameters were calculated for the shear stress for all cases. both for OBE, and SSE:

1. Sample Mean 00

II. Standard Deviation (s)

These statistics were then used as the parameters for the distribution of the population.

The statistical distribution assumed generally applicable for the data Is the Gamma distribution. The main reason for this is that the data never takes on negative values. The Gamma distribution is defined by:

k-i -Xx f(x) = X(Xx)k-1C. x (k-1) !

X>O

7

0

and has a mean value of k/. and a coefficient of variation I/AC it is to be noted though that for k > 15. the Gamma and the Normal distributions are extremely close and that the Normal distribution is assumed for those cases.

The 95% confidence interval for the mean of the population Mt was calculated, assuming that the normalized variable

S / /n

Is t-distributed. and that the actual population standard deviation. K is unknown. Here n is the sample size.

For the Gamma distribution, confidence intervals on parameters such as m -k 0" have no meaning and must be reinterpreted. On the normal curve m -10" corresponds to a point on the cumulative distrjbution curve with an ordinate of 0.1587. This means that approximately 16% of the area under the probability density curve lies to the left of m -1a' . Similarly, m -2Tand m -30' correspond to points with ordinates 0.02275 and 0.00135, respectively. Based on the confidence interval for the mean, confidence intervals were calculated for values of the Gamma distribution for which the cumulative distribution function had values of 0.1587. 0.02275 and 0.00135. respectively.

The results from this analysis are presented in Tables 3-2 and 3-3.

The results were then compared with the criteria specified factors on the ATh' for the allowable shear stress as given in Table 3-1.

TABLE 3-1

8

Probabilities that the criteria specified allowable stress would exceed

the stress based on the test results were calculated under two

assumptions: firstly, that the population mean was equal to the sample

mean. and secondly. that It was at the lower end of the 95% confidence

Interval.

Finally, safety factors based on the 95% confidence Interval for the

mean were calculated for the shear stresses.

These results are presented In Table 3-4.

9

r~.

0TABLE 3-2

MASONRY TAKES THE SHEAR

= 0.25 M 0.5 1.0 VdVd - 1.0

OBE:*

Sample Size 1 4 7 Sample Mean (m) 3.476 2.465 2.471 Standard Deviation (s) - 0.703 0.362 Coeff. of Variation 28.5% 14.6%

95% Confidence Interval:

On (m) - 1.347 < m < 3.583 2.136 < m f 2.806 On (m-s) - 0.662 f m-s < 2.880 1.774 m m-s f 2.444 On (fi-2s) - 0.334 < m-2s f 2.177 1.412 m-2s L 2.082 On (m-3s) - 0.125 < im-3s f 1.474 1.050 f im-3s 1 1.720

Sample Size 1 4 7 Sample Mean (m) 4.500 2.844 2.594 Standard Deviation (s) - 0.627 0.379 Coeff. of Variation 22.0% 14.6%


On (m) - 1.846 f m f 3.842 2.243 f m i 2.945 On (m-s) - 1.225 rn-s i1 3.215 1.864 f M-s - 2.566 On (m-2s) - 0.807 m m-2s < 2.588 1.485 f m-2s f 2.187 On (m-3s) - 0.502 f m-3s f 1.961 1.106 f m-3s S 1.808

0

TABLE 3-3

REINFORCEMENT TAKES THE SHEAR

M M M Vd 0.25 = 0.5 M = 1.0

OBE: Sample Size 5 10 (4) 6 Sample Mean (m) 4.113 3.344 (4.531 ) 3.233 Standard Deviation (s) 0.398 1.251 (0.752 ) 0.250 Coef. of Variation 9.7% 37.4% (16.6%) 7.7%


2.449 1 m L 4.239

On (m) 3.619 m m . 4.607 (3.334 . m 5 5.728 ) 2.971 m m - 3.495 1.277 < m-s < 3.007

On (m-s) 3.221 . m-s - 4.209 (2.582 - iri-s . 4.976 2.721 . m-s . 3.245 0.646 < m-2s < 2.122

On (m-2s) 2.823 < m-2s 1 3.811 (1.830 L m-2s < 4.224 ) 2.471 1 m-2s 1 2.995 0.284 < m-3s < 1.440

On (m-3s) 2.425 < m-3s 3.413 (1.078 . m-3s 3.472 ) 2.221 1 m-3s 1 2.745

SSE: Sample Size 5 10 (4) 6 Sample Mean (m) 5.247 4.111 (5.117 ) 3.588 Standard Deviation (s) 0.548 1.251 (0.415 ) 0.365 Coeff. of Variation 10.4% 30.4% (8.1%) 10.2%

95% Confidence interval: 3.216 m m 1 5.006

On (m) 4.567 m m . 5.927 (4.457 . m - 5.777 ) 3.205 - m - 3.971 1.988 L m-s 1 3.755

On (m-s) 4.019 m-s - 5.379 (4.042 -L m-s 1 5.362 ) 2.840 m-s . 3.606 1.212 < m-2s < 2.504

On (m-2s) 3.471 1 m-2s 1 4.831 (3.627 . m-2s . 4.947 ) 2.475 - m-2s - 3.241 0.683 < m-3s 1 1.253

On (m-3s) 2.923 f m-3s 1 4.283 (3.212 m m-3s f 4.532 ) 2.110 m m-3s 2.876

The numbers in parentheses come from evaluation of yet unpublished data from tests at U.C., Berkeley.

0TABLE 3-4

Masonry Takes the Shear Reinforcement Takes the Shear

M M M MM = 0.25 = 0. 5 1. M = 0.25 = 0.5

OBE

Probability of Exceedence:

KEY A - 52/1,000 13/1,000.000 0 * 79/1.000 0 a

(108/1,000,000)

KEY B - 62/100 320/1.000.000 45/1.000.000 32/100 0 a

(18/1.000)

Range of Safety Factors 2.02 0.93 - 2.47 2.37 - 3.12 1.93 - 2.46 1.40 - 2.42 1.98 - 2.33

On the Mean (1.91 - 3.27)

OSE

Probability of Exceedence:

KEY A 26/100 1926/1.000.000 78/1.000.000 173/1.000 14/10,000

(0 A)

KEY B 69/100 25/1.000 6/1,000 47/100 27/1.000

(142/1.000.000)

Range of Safety Factors 1.54 0.75 - 1.57 1.50 - 1.96 1.44 - 1.87 1.09 - 1.70 1.28 - 1.59

On the Mean (1.51 - 1.96)

* Probabilities of exceedence less than 1 In 1,000.000.

Values In parenthesis come from evaluation of yet unpublished data from tests at U.C. Berkeley.

3.2.3 Discussion of Results

The tests performed at U.C. Berkeley were performed under different conditions and on smaller units than generally exist at the Monticello plant. However, because most of the Monticello walls have a boundary support both at top and bottom, they are considered comparable to the test walls which had only such top and bottom boundaries. Furthermore. It is our belief that the Berkeley test walls were of a sufficient size to be applicable to a general wall of similar height to width ratios.

In the following discussion, note that due to the top and bottom fixity of the test specimens. the M/Vd ratio equals half the height-to-width ratio.

Looking at the values of Table 3-4. we see that in general the results for M/Vd = 0.5 have a much higher probability of exceedence than do the other values. Unfortunately. some of the walls tested in that series were subject to unforeseen problems with the test setup and which had some adverse effects on the results. A relatively low confidence is thus placed on those tests. Four tests whose results have not yet been published have since been performed on walls with M/Vd = 0.5. but only for the case where the reinforcement takes the shear. The 'results of a statistical analysis of those tests are presented in Tables 3-2. 3-3 and 3-4 in parentheses. The results on which we place a lower confidence will be ignored in the subsequent discussion. In general. the probabilities of exceedence are low. It can be stated that criteria allowable shear stress will exceed the actual - value determined from tests 108 times in 1.000.000 (0.01%) for OBE events and 1926 times in 1.000,000 (0.19%) for SSE events if the population mean strength is taken at the center of the 95% confidence interval. If one considers the extreme case where the population mean is taken to be at the lowest end of the 95% confidence interval, then these figures become 18 in 1,000 (1.8%) for OBE events and 27 in 1,000 (2.7%) for SSE events. Given the extreme nature of the assumption on which these second estimates are based, these probabilities of exceedance are deemed satisfactory.

By taking the 95% confidence intervals on the population mean, the factor of safety associated with the criteria allowable shear stresses for the case of the masonry taking the shear is 2.02 ( SF < 3.12 and 1.50 < SF < 1.96 for OBE and SSE events. respectively. For the case of reinforcement taking the shear, these values are 1.91 < SF < 3.27 and 1.28 < SF < 1.96 for OBE and SSE events, respectively.

3.3 CONCLUSIONS

In view of the above discussion of results, It is concluded that the criteria specified increase factor for shear stresses of 1.67 - 1.7 for factored loads is reasonable for the reevaluation of the Monticello Nuclear Generating Plant.

13

3.4 REFERENCES

1. Mayes. R.L. Omote. Y.. and Clough, R.W.. 'Cyclic Shear Tests of Masonry Piers. Volume 1 - Test Results.* EERC Report No. 76-8. May. 1976.

2. Hidalgo. P.A.. et al.. "Cyclic Loading Tests of Masonry Single Piers. Volume 1 - Height to Width Ratio of 2.0. EERC Report No. 78-27. November 1978.

3. Chen. S.W.. et al.. *Cyclic Loading Tests of Masonry Single Piers. Volume 2 - Height to Width Ratio of 1. EERC Report No. 78-28. Dec.. 1978.

4. Hidalgo. P.A.. et al.. 'Cyclic Loading Tests of Masonry Single Piers. Volume 3 - Height to Width Ratio of 0.5.' EERC Report No. 79-12. May, 1979.

5. Sveinsson. B.L.. et al.. 'Evaluation of Seismic Design Provisions for Masonry in the United States.' EERC Report 81-10, August 1981.

14

STIFFEN TOP WF BEAM(ADDED)(WI4x151) TOP WF BEAM (ORIGINAL)( WI4 x 127)

ACTUATORS FORCESP DISPLACEMENT CONTROLLED

STRONG (MTS SERVO JACKS) BACK CONNECTED TO

LOAD CELL REACTION FRAME

ACTUATOR V - V(P) FORCE CONTROLLED

CONCRETE BASE BLOCK

' -- FLOOR LEVEL

STEEL PLATE WITH HEAVY SHEAR KEYS (TOP AND BOTTOM)

FIGURE 3-1

TTOM WF BEAM (W14 x127)

SCHEMATIC ILLUSTRATION OF SINGLE PIER TEST

0

U'

H/W RATIO = 0.5

\,. ... :

,,. ,. 11 .,*.*..A Stage 12 1

SUCCESSIVE CRACK FORMATION AND EXPERIMENTAL RESULTS, TEST HCBL-12-3

-*

Stage 10

Stage 16

I

FIGURE 3-2

H/W RATIO 1.0

n .m

-- c J3 S. Sc.1 I

L -a-r

FIGURE 3-3 SUCCESSIVE CRACK FORMATION AND

EXPERIMENTAL RESULTS. TEST HCBL-11-4

17

H/W RATIO = 2.0

-4- V :RECT1ON

- VE LATERAL DISPL. CORRES SMEAR FCRCE AND SMEAR STRESS -dE LATERAL DISPL.CORRES. SMEAR FCRCE AND SMEAR STRESS

0.16"; 23.O KIPS 120 PSI

0.13"; 20.1KIPS 150 PSI

~W~4 -~ -

~ ~.

- ~

0.29"; 18.8 KIPS 98 PSI

0.18"; 21.7 KIPS 113 PSI

I..,

'11

.1

0.32"; 19.9 KIPS 104 PSI

0.24 , 19.1 KIPS 99 PSI

104 PSI 55PSI ; 19.7 KIPS 0.41"; 13.6 KIPS 0.7"

102 PSI 71 PSI

FIGURE 3-4 SUCCESSIVE CRACK FORMATION AND

EXPERIMENTAL RESULTS, TEST HCBL-21-6

"18

0.28'

1

4 BOND

The specified increase of 1.33 for reinforcement bond for factored loads is in accordance with the 1979 UBC. Section 2303(d). This section is partly in reference to Table 24-H and items 9 and 10 of that table specify the same allowable values for reinforcement bond at a working stress level as does the 'Criteria for the Reevaluation of Concrete Masonry Walls - Monticello Nuclear Generating Plant.' Furthermore. the UBC permits an Increase of 1.33 In this allowable stress for seismic loads. Thus the specified Increase of 1.33 for factored loads Is in accordance with the 1979 UBC.

19

5 TENSION NORMAL TO BED JOINT

The following is a justification for using a stress increase factor of 1.67 for tension normal to the bed joint for factored loads.

5.1 Overview of Test Programs

The results of six different test programs regarding the tensile strength of mortar normal to the bed joint are evaluated in this report. All the test programs reported in references 1 through 6 Involved static. monotonic load tests.

The test programs provided results for 81 unreinforced test specimens. Involving four different mortar types. namely. M. S. N and 0 as specified by proportion in ASTM C270. Also varying between the six test programs was the way in which the wals were loaded. Some tests were performed using a uniform pressure (air bag) loading, some used concentrated center point loading. and others were performed with concentrated loads at the quarter points of the wall. The uniform load produces a parabolic moment distribution over the height of the wall, the central loading condition produces a symmetric triangular distribution with a maximum at midspan. and the quarter point loading produces a region of constant moment over half the height of the wall. In one series of experiments (3) the walls were tested after only 15 days of curing.

5.1.1 Applicability of Test Results

The results of the 81 tests performed in the six static test programs. In our opinion, are applicable in determining the tensile strength normal to the bed joints. for seismic loads, for the following reasons:

1. An unreinforced masonry wall responds elastically to seismic loads provided it is not cracked. This was demonstrated in some of the shaking table tests.

2. There are no test results available indicating that dynamic loading reduces the tensile strength normal to the bed joint. In fact. the only test data available for any type of cyclic loading on masonry structural elements indicates that the in-plane shear strength of masonry shear walls tested pseudostatically is 8-23% less than that of a 3 cps equivalent dynamic test (Reference 7).

20

3. Cyclic or shake table tests are essential to determine the post-cracked or Inelastic performance of structural elements. However, they are not essential to determine the ultimate or cracking strength of structural elements.

4. Points 1. 2 and 3 above indicate that the uniform or point load tests are reasonable methods -to determine the cracking or tensile strength of an unreinforced masonry wall subjected to out-of-plane loads.

21

5.2 Evaluation of the Test Results

The results from six different monotonic test programs (1. 2. 3. 4. 5. 6) on the tensile strength of mortar normal to the bed joint form the basis of the statistical analysis presented In this section. In total, data from 81 tests were available, involving four different mortar types. namely. types M. S. N and 0. Only the results of tests with type M mortar. as specified by proportion in ASTM C270. are used herein as this was the mortar type specified for the 'Monticello Nuclear Generating Plant. Tests reported in (2). (3). (4). and (5) contain no data for type M mortar, and thus have no further part in this study.

Table 5-1 shows a summary of the remaining tests on type M mortar.

TABLE 5-1

No. of Reference Tests Loading Comments

1. 3 Uniform Section Modulus Based on Mortar Bedded Area

6 4 Uniform Section Modulus Based on Mortar Bedded Area

Tensile strength 'normal to the bed joint is influenced by several variables. perhaps the single most Important of which is the mortar cube strength. The 7 samples with type M mortar cover a range of cube strengths from 3000 psi on the low end to 5100 psi on the high end. The effect of this variable is taken into consideration when evaluating the tensile strengths applicable at Monticello.

5.2.1 Description of Statistical Analyses

Statistical analyses were performed for the uniform load data. A plot of the tensile strength normal to the bed joint against the corresponding mortar cube strength was then made for all the data. This plot is shown in Figure 5-1. Two least squares fits to this data were then made. The first was of the form:

Y = k x n

22

C,

.....

and the second was of the form:

Y= kv

where

Y = tensile strength normal to bed joint X = mortar cube strength

The resulting curves are also plotted in Figure 5-1. The two curves differ considerably. which is not surprising considering the close grouping of the available data. especially the lack of low-strength data. In view of a study of all available data for type N mortar (Figure 5-2). the use of the tensile strength as a function of the square root of the cube strength is reasonable. In view of the ACI-531 code use of functions involving the square root of the mortar cube strength, the second curve will be used herein. Accepting this relationship between tensile bond strength and mortar cube strength, all data can then be normalized by dividing the test tensile strength by the square root of the corresponding mortar cube strength. The following parameters were then computed:

(I) Sample Mean. X

(i) Sample Standard Deviation. s

These statistics were then used as the parameters for the distribution of the population. Two underlying distributions were assumed. and the effect of the choice of distribution on the results was examined. The more reasonable distribution was then accepted. The two underlying distributions were the normal distribution and the gamma distribution. The 95% confidence Interval for the mean of the population m was calculated, assuming that the normalized variable:

X - m

s/ /n

is t-distrlbuted. and that the actual population standard deviation. (T, is unknown.. Here n is the sample size.

For the case of the underlying distribution being normal, confidence intervals on the parameters m-la', m-20 and m-3<f were estimated from the confidence interval on the mean and the sample standard deviation. For the case of the underlying distribution being gamma. a different approach was taken. m-10r corresponds to a value of the cumulative distribution function equal to 0.1587 for the normal distribution. This means that a little under J6% of the area under the probability density curve lies to the left of m-107. Similarly. m-2cr and m-30 correspond to values of 0.02275 and 0.00135 on the cumulative distribution

23

function, respectively. Based on the confidence interval for the mean. confidence intervals were calculated for values of the gamma distribution for which its cumulative distribution function had values of 0.1587. 0.02275 and 0.00135. respectively.

These actual distributions were then compared with the criteria specified allowable tensile stress normal to the bed joint. I.e.. 0.5 41M for the OBE condition. and 1.67 times that value for the SSE condition. Probabilities that the criteria specified allowable stress would exceed the actual joint strength based on the test results and scaled to a mortar cube strength of 2500 and 3600 psi were calculated under two assumptions: firstly. that the population mean was equal to the sample mean, and secondly. that It was at the lower end of the 95% confidence interval. These conditions are termed A and B. respectively. in Table 5-4.

Finally safety factors based on the 95% confidence Interval for the mean were calculated.

5.2.2 Results of Statistical Analyses

5.2.2.1 Sample Statistics

In Table 5-2 below, the test tensile strengths normal to the bed joint have been normalized by dividing each strength by the square root of the corresponding mortar cube strength.

TABLE 5-2

Normalized Uniform Load Data

Sample Size 7 Sample Mean 1.5522 Sample Standard Deviation 0.1439 Coefficient of Variation 9.3%

24

5.2.2.2 Confidence Intervals on the Population Mean

The normalized variables analyzed in Section 6.2.2.1 are transformed to real tensile strengths normal to the bed joint by multiplying the normalized variable by the square root of the actual specified cube strength of interest. In the case of the Monticello Nuclear Generating Plant. the appropriate cube strength is in the range 2500 - 3600 psi.

The following confidence intervals result:

Mo = 3600 psi: 85.1 s m s 101.1 psi

Mo = 2500 psi: 71.0 j m S 84.3 psi

5.2.2.3 Discussion of Normal vs. Gamma Distribution

The normal distribution Is well known and requires no discussion other than the fact that it is a symmetric distribution with possible values In the range (-00. 00). We are concerned in this study with data that can only assume positive values (tensile strength). and this Is a possible problem with using the Normal distribution. because It can assume negative values. The Gamma distribution, on the other hand. cannot assume negative values and its shape may be adjusted by varying the parameters k and 1.

k-1 -Xx f(x) = XX~ x (k-1)1

The distribution has a mean value of k / A and a coefficient of variation of 1/ OV Thus the value of k. Is adjusted to give the coefficient of variation observed from' the sample. and then X is calculated to give the correct mean value. The following values of k and A arise:

k = 116

2 = 74.73

For large k 015), the Gamma distribution and the Normal distribution are extremely close. Thus the normal distribution is used for the data.

It should be noted that there is no physical reason why tensile strengths normal to the bed joint should have any particular distribution. However, the Gamma distribution can assume a wide variety of shapes by varying the parameters k and ) .

25

5.2.2.4 95% Confidence Intervals

At Cumulative Distribution ( Cr Level)

Function = 0.1587

(Me = 3600): 76.5 psi S. X 1 92.5 (M. = 2500): 63.8 psi 4 X 1 77.1

At Cumulative Distribution (2 cr Level):

Function = 0.02275

(Me = 3600): 67.9 psi I X 1 83.9 psi (Me = 2500): 56.6 psi 1 X i 69.9 psi

(iDi0: At Cumulative Distribution (307 Level):

Function = 0.00135

(M.o = 3600) 59.2 psi 1 X 75.2 psi (M. = 2500): 49.4 psi I X S, 62.7 psi

These Intervals are displayed graphically in Figure 5-3.

5.2.2.5 Safety Factors Based on the Mean

The reevaluation criteria specifies that the cube. strength for type M Mortar shall be limited to Me = 2500 ps,. This leads to *allowable' tensile stresses normal to the bed joint of 25 psi for the OBE condition and 41.5 psi for the SSE condition.

Using the above values for the OBE and SSE conditions, and the 95% confidence Interval for the mean strength from the tests. scaled to a cube strength of 3600 psi, the following limits arise for the safety factor based on the mean.

TABLE 5-3

26

(iDO:

(D)

5.2.2.6 Probabilities of Exceedance

The probabilities that the code specified allowable stress will exceed the available strength based on the test results are as shown in Table 5-4.

TABLE 5-4

Normal Distribution

Case Key OBE SSE

Uniform Load A 1012 10-9 - 12 (M0 = 3600 psi) B 10 0.0000003 -13 (M0 = 2500 psi) A 10-10 0.0000003

B 10 0.00003

Note:

1. A gives the probabilities of exceedance assuming the population mean equals the sample mean. B gives the probabilities of exceedance assuming the population mean is at the lower end of the 95% confidence interval.

5.2.3 DISCUSSION OF RESULTS

The key results for the confidence intervals are plotted in Figure 5-3. together with the OBE and SSE stresses from the reevaluation criteria.

The confidence intervals for the data are relatively narrow although the sample size was small. It Is seen that both the OBE and SSE stresses lie well below the 'mean minus three standard deviationso confidence interval for both cube strength projections. This is consistent with the very low probability that the reevaluation criteria stresses will exceed the actual tensile strength as presented In Section 5.2.2.6.

It can be stated that criteria specified allowable stresses will practically never exceed the actual tensile strength of the mortar normal to the bed joint for OBE events and at most 3 times in 10.000.000 for SSE events if the population mean strength is taken at the center of the 95% confidence interval. If one considers the extreme case where

27

0

the population mean is taken to be at the lower end of Its 95% confidence Interval, then these probabilities hardly change for an OBE event. but change to 30 times in 1,000.000 for an SSE event. These probabilities of exceedance are deemed very satisfactory.

Alternatively. Instead of calculating probabilities of exceedance, one may take the same data and calculate factors of safety based on the mean. If this is done for the OBE events. using the full range of the 95% confidence Interval for the population mean, and taking the extremes from both cube strength cases, the safety factor lies in the range of 2.84 < SF ( 4.04. Similarly, for SSE events, the range is 1.71 ( SF < 2.44.

5.3 CONCLUSIONS

The purpose of Item 11-d was to provide a detailed analysis of the available test data to justify the allowable tensile stresses normal to the bed joint used in the reevaluation criteria. The values specified in the revised criteria are 0.5.,W for an OBE event and 0.834 for an SSE event. Thus the allowable tensile stresses normal to the bed joint are limited to 25.0 psi for an OBE event and 41.5 psi for an SSE event. In view of the statistical analysis presented herein. this cut-off at 2500 psi for the mortar strength is reasonable.

The range of the factors of safety, based on the test data and scaled to a cube. strength of 2500 psi. Is 2.84 to 3.37 for an OBE event and 1.71 to 2.03 for an SSE event. These factors of safety .are based on the 9.5% confidence Intervals of the mean strength of the test data. It Is therefore concluded that the allowable tensile stresses normal to the bed joint of 25.0 psi and 41.5 psi for OBE and SSE events respectively are reasonable values to use In the reevaluation criteria for the Monticello Nuclear Generating Plant.

28

5.4 REFERENCES

1. Copeland. R.E.. and Saxer, E.L.. "Tests of Structural Bond of Masonry Mortars to Concrete Block.* Proceedings. American Concrete Institute. Vol. 61. No. 11. Nov.. 1964.

2. Hedstrom. R.O.. 'Load Tests of Patterned Concrete Masonry Walls.' Proceedings. American Concrete Institute. Vol. 57. P. 1265. 1961.

3. Fishburn. Cyrus C.. "Effect of Mortar Properties on Strength of Masonry." Monograph 36. National Bureau of Standards. 1961.

4. Whittemore. S.L.. Stang, Ambrose H.. and Parsons. 'Structural Properties of Six Masonry Wall Constructions.' Building Materials and Structures Report No. 5. National Bureau of Standards. 1938.

5. Richart. Frank E.. Moorman, Robert B.B.. and Woodworth. Paul. "Strength and Stability of. Concrete Masonry Walls.' Bulletin No. 251, Engineering Experiment Station. University of Illinois. 1932.

6. Unpublished Data. National Concrete Masonry Association.

7. . Mayes. R.L.. Omote. Y.. and Clough. R.W.. 'Cyclic Shear Tests of Masonry Piers. Volume 1: Test Results." EERC Report No. 76-8. May 1976.

8. Monk. C.B.. 'Transverse Strength of Masonry Walls.' Special Publication No. 166. American Society for Testing and Materials. 1954.

9. 'Research Data and Comments in Support of: Recommended Building Code Requirements for Engineered Concrete Masonry," National Concrete Masonry Association.

29

41

120 t 1.543F(

0D 0.0831

100- t f 49.90 m

bJ z 0E w

w 80

0

S60- KEY: 0j Reference 1

CA 0Reference 6

z uJ 40

w -J

z w 20

1000 2000 3000 4000 6000 6000 7000 8000

n- MORTAR CUBE STRENGTH (psi) TYPE M Mortar

FIGURE 5-1 TENSILE STRENGTH VS MORTAR CUBE STRENGTH

0

0l 0

0op

Iz

m 0 0 z I0

I-J ra z

00 w. **

50

40

30

20

10

u~ 010 s

0 - 0.306

de3462 m ..

D E

/ / /,

"I

I,

El0

KEY: 0

0

El

Reference 3

Reference 4

Reference 5

- I

61

FIGURE 5-2

00 1000 1500

me - MORTAR CUBE STRENGTH (pal)

TENSILE STRENGTH VS MORTAR CUBE STRENGTH

I II

2000

TYPE N Mortar

I

60

0

c

00 0

E)

de0 001.0 0000

00 Ole o0' * 4-0 Q.)

OBE

25pal

IL

SSE

41.5 PS4-- Re-evaluation criteria

Ll

LIIIKEY: LI1m: =3600 psi

m ... 2500 psi

LIZII

40 60 80 100 120f (psi)

t95% CONFIDENCE INTERVALS ON ft

CONFIDENCE INTERVALS FOR POPULATION STATISTICS

C w S

LL

La. 0 C)to

u)

co1

io coI 0 0

J.%

t NV

LC) C)

20

I I

FIGURE 5-3

............................... . -

6 TENSION PARALLEL TO THE BED JOINT

The following Is a justification for using a stress increase factor of 1.67 for tension parallel to the bed joint for factored loads.

6.1 AVAILABLE TEST RESULTS

The results of two different test programs regarding the flexural strength of masonry in the horizontal span. parallel to the bed joint are evaluated in this report. Both test programs given In References 1 and - 2 Involved static monotonic load tests.

The test programs provided results for 36 test specimens involving three different types of mortar. namely. M. N and 0 as specified by proportion in ASTM C270. All 36 specimens were loaded using concentrated center line loading which produces a symmetric triangular moment distribution with a maximum at midspan.

6.1.1 APPLICABILITY OF TEST RESULTS

The results of 36 tests performed in the two static test programs. In our opinion, are applicable in determining the tensile strength normal to th§ bed joints, for seismic loads, for the same reasons given in Section 5.1.1.

6.2 EVALUATION OF MONOTONIC TEST RESULTS

The results from two different monotonic test programs (1.2) on the tensile strength of mortar parallel to the bed joint form the basis of the statistical analysis presented in this section. In total, data from 36 tests were available. involving three different mortar types. namely types M. N and 0. Only the results of tests with type M mortar, as specified by proportion in ASTM C270. are used herein as this was the mortar type specified for the Monticello Nuclear Generating Plant.

The specifications for the test series reported In Reference 2 called for a* type M mortar for all 12 specimens. Due to a failure of a mason to follow the speciflatlons. the mortar used was much richer and thus cannot be defined as a type M mortar. Therefore the tests reported in (2) have no further part in this study.

The test series reported In (1) has results from 24 tests, six involving type M mortar and 12 and six involving type N and type 0 mortar, respectively. The six tests Involving the type M mortar are, although few in numbers. analyzed statistically herein.

Tensile strength parallel to the bed joint is influenced by several variables Including the mortar shear strength. mortar cube strength and block modulus of rupture. The code writing committees. specifically ACI (ACI-531), choose

33

to relate the design allowable stresses to the mortar cube strength. The statistical analysis In this report is directed towards the same.

The mortar strength reported for the specimens was just the average of results obtained in tests of three 2-in. cubes at an age of 28 days. Thus. there is only one mortar cube strength value to work with. This limits the generality of the analysis somewhat, but because the reported cube strength (2743 psi) is close to the minimum code specified value (2500 psi) for type M mortar, the analysis is considered justifiable.

6.2.1 Description of Statistical Analyses

For the purpose of this analysis due to limited data. the ACI-531 assumed relationship. Le.. y=constant f A!"' is accepted. The data was then normalized by dividing the test tensile strength by the square root of the mortar cube strength. The following parameters were then computed:

(1) Sample Mean. X

(1l) Sample Standard Deviation. s

These statistics were then used as the parameters for the distribution of the population. At first two underlying distributions were assumed., and the effect of the choice of distribution on the results was examined. The more reasonable distribution was then accepted. The two underlying distributions were the normal distribution and the gamma distribution. The 95% confidence interval for the mean of the population m was calculated, assuming that the normalized variable:

X - m

is t-distributed. and that the actual population standard deviation. a , is unknown. Here n is the sample size.

For the case of the underlying distribution being normal, confidence intervals on the parameters m-li', m-2o' and m-3cr were estimated from the confidence Interval on the mean and the sample standard deviation. For the case of the underlying distribution being gamma. a different approach was taken. m-le' corresponds to a value of the cumulative distribution function equal to 0.1587 for the normal distribution. This means that a little under 16% of the area under the probability density curve lies to the left of n-l'. Similarly, m-2o' and m-3a correspond to values of 0.02275 and 0.00135 on the cumulative distribution function, respectively. Based on the confidence Interval for the mean. confidence Intervals were calculated for values of the gamma distribution for which its cumulative distributlop function had values of 0.1587, 0.02275 and 0.00135. respectively.

34

This actual distribution is then compared with the criteria specified allowable tensile stress parallel to the bedjoint. i.e. 1.0/i? for the OBE condition and 1.67 times that value for the SSE condition. Probabilities that the criteria specified allowable stress would exceed the actual joint strength based on the test results and scaled to a mortar cube strength of 2500 and 3600 psi were calculated under two assumptions: firstly, that the population mean was equal to the sample mean, and secondly. that it was at the lower end of the 95% confidence interval. These conditions are termed A and 8. respectively. in Table 6-3.

Finally safety factors based on the 95% confidence interval for the mean were calculated.

6.2.2 Results of Statistical Analyses

6.2.2.1 Sample Statistics

in the table below. the test tensile strengths parallel to the bed joint have been normalized by dividing each strength by the square root of the corresponding mortar cube strength.

TABLE 6-1

Normalized Uniform Load Data

Sample Size 6 Sample Mean 4.175 Sample Standard Deviation 0.311 Coefficient of Variation 7.5%

6.2.2.2 Confidence Intervals on the Population Mean

The normalized variables analyzed in Section 6.2.2.1 are transformed to real tensile strengths normal to the bed joint by multiplying the normalized variable by the square root of the actual specified cube

35

strength of interest. In the case of the Monticello Nuclear Generating Plant, the appropriate cube strength Is in the range 2500 - 3600 psi.

The following confidence Intervals on the mean result:

For Mo = 3600 psi: 230 1 m s 270.1 psi

For Mo = 2500 psi: 192.5 s m 1 225.1 psi

6.2.2.3 Discussion of Normal vs. Gamma Distribution

The normal distribution is well known and requires no discussion other than the fact that it Is a symmetric distribution with possible values in the range (-00. 00). We are concerned in this study with data that can only assume positive values (tensile strength), and this Is a possible problem with using the Normal distribution. because it can assume negative values. The Gamma distribution, on the other hand, cannot assume negative values and its shape may be adjusted by varying the parameters k and A.

k-i -XX f )(Xx) . x (k-1)

The distribution has a mean value of k / k and a coefficient of variation of 1/ X' Thus the value of k is adjusted. to give the coefficient of variation observed from the sample. and then 2 is calculated to give the correct mean value. The following values of k and > arise:

k = 178

)L = 42.582

For large k 015), the Gamma distribution and the Normal distribution are extremely close. Thus the Normal distribution Is used for the data.

It should be noted that there is no physical reason why tensile strengths normal to the bed joint should have any particular distribution. However, the Gamma distribution can assume a wide variety of shapes by varying the parameters k and X .

36

6.2.2.4 95% Confidence Intervals

(III):

At Cumulative Distribution Function = 0.1587 (1 4 Level)

(M. = 3600): 212.3 psi i. X j 251.4 (Me = 2500): 176.9 psi . X S. 209.5

At Cumulative Distribution Function = 0.02275 (2 0 Level):

(M. = 3600): 193.6 psi t X 1 232.7 psi (Me = 2500): 161.4 psi s X 1 194.0 psi

At Cumulative Distribution Function = 0.00135 (37 Level0:

(M. 3600) 175.0 psi iXi1 214.1 psi (M. = 2500): 145.8 psi I X 1 178.4 psi

These intervals are displayed graphically in Figure 6-1.

6.2.2.5 Safety Factors Based on the Mean

The reevaluation criteria specifies that the cube strength for type M mortar shall be limited to Me = 2500 pst: This leads to 'allowable" tensile stresses parallel to the bed joint ( VW ) of 50 psi for the OBE condition and 83.5 psi for the SSE condition.

Using the above values for the OBE and SSE conditions, and the 95% confidence interval for the mean strength from the tests, scaled to a cube strength of 2500 and 3600 psi, the following limits arise for the safety factor based on the mean.

TABLE 6-2

OBE SSE

M = 3600 psi 4.62 < SF ( 5.40 2.77 < SF ( 3.23 0 - .

M = 2500 psi 3.85 < SF < 4.50 2.31 < SF < 2.70 0O

037

()

(iD:

6.2.2.6 Probabilities of Exceedance

The probabilities that the code specified allowable stress will exceed the available strength based on the test results are as follows:

TABLE 6-3

Normal Distribution

Case Key OBE SSE

M = 3 600 psi A 0 0 B 0 10-1s

M = 2500 psi A 0 10-16 B 0 10

Notes:

1. A gives the probabilities of exceedance assuming the population mean equals the sample mean. B gives the probabilities of exceedance assuming the population mean is at the lower end of the 95% confidence interval.

2. A probability less than 10-16 is considered zero.

38

*d *~**

6.2.3 DISCUSSION OF RESULTS

The key results for the confidence intervals are plotted in Figure 6-1. together with the OBE and SSE stresses from the reevaluation criteria. The confidence intervals for the data are relatively narrow although the sample size was small. It is seen that both the OBE and SSE stresses lie well outside the "mean minus three standard deviations" confidence Interval for both cube strength projections. This Is consistent with the values for probabilities that the reevaluation criteria stresses will exceed the actual tensile strength as presented in Section 6.2.2.6.

It can be stated that criteria specified allowable stresses will. In all practicality, neither exceed the actual tensile strength of the mortar parallel to the bed joint for an OBE event nor an SSE event.

Alternatively. Instead of calculating probabilities of exceedance. one may take the same data and calculate factors of safety based on the mean. If this is done for the OBE events, using the full range of the 95% confidence interval for the population mean. and taking the extremes from both cube strength cases, the safety factor lies In the range of 3.85 < SF < 5.40. Similarly. for SSE events, the range is 2.31 < SF < 3.23.

6.3 CONCLUSIONS

The purpose of Item 11-e was to provide a detailed analysis of the available test data to justify the allowable tensile stresses parallel to the bed joint used in the reevaluation criteria. The values specified In the revised criteria are 1.0073' for an OBE even and 1.67073' for an SSE event. Thus the allowable tensile stresses parallel to the bed joint are limited to 50.0 psi for an OBE event and 83.5 psi for an SSE event. In view of the statistical analysis presented herein, this cutoff at 2500 psi for the mortar strength is conservative.

The range of the factors of safety. based on the test data and scaled to a cube strength of 2500 psi. Is 3.85 to 4.50 for an OBE event and 2.31 to 2.70 for an SSE event. These factors of safety are based on the 95% confidence intervals of the mean strength of the test data.

It Is therefore concluded that the allowable tensile stresses parallel to the bed joint of 50.0 psi and 83.5 psi for OBE and SSE events, respectively, are reasonable values to use in the reevaluation criteria for the Monticello Nuclear Generating Plant.

39

6.4 REFERENCES

1. Livingston. AR.. Mangotich. E.. and Dikkers. R.. "Flexural Strength of Hollow Unit Concrete Masonry Walls in the Horizontal Span.* Technical Report No. 62. NCMA. 1958.

2. Cox. F.W.. and Ennemga. J.L. *Transverse Strength of Concrete Block Walls.* Proceedings. ACI. Vol. 54. p. 951. 1958.

3. Mayes. R.L. Omote. Y.. and Clough. R.W.. 'Cyclc Shear Tests of Masonry Piers. Volume 1: Test Results.' EERC Report No. 76-8. May 1976.

40

4- Re-evaluation Criteria1~~

OBE

50. psi

I

I

Ij

50

FIGURE 6-1

100 150 200 250 300 f (psi) t

95% CONFIDENCE INTERVALS ON f t

CONFilENCE INTERVALS FOR POPULATION STATISTICS

-j

SSE

83.5 Pal

I.

KEY:

mo = 3600 psi

mo= 2500 psi

II3-

U

U.

U_

0O

to

0

to co V_ c 00 0


12.0 NRC COMMENT

'With reference to Table 2 in reference 3, justify the formula used for allowable stress in Grout Core Tension.

Response

Because the item in question, the grout core tension allowable, was never used in the reevaluation of Masonry Walls in the Monitcello Nuclear Generating Plant, it has now been removed from the reevaluation criteria. With this response a revised criteria as of April 1982 is attached.

12-1

CRITERIA FOR THE RE-EVALUATION

OF CONCRETE MASONRY WALLS

Monticello Nuclear Generating Plant

R2/4

14

CONTENTS

1.0 GENERAL . . . . . . . . . . . . . . . . .1

1.1 Purpoe. . . . .. . . . . . .. . . . .. . . . . . .

2.0 GOVERNING CODES . . . . . . . . . . . . . . 1

3.0 LOADS AND LOAD COMBINATIONS . . . . .... . . . . . 1

3.1 Service Load Conditions . . . . . . . . . . . . . 1 3.2 Factored Load Conditions... . . . . . . . . 2

3.3 Definition of Terms . . . . . . . . . . . . . . 2

4.0 MATERIALS ...... ... . . . . . . . . ..... . 2

4.1 Concrete Masonry Units . ....... ...... . 2

4.2 Mortar . . . . . . . . . . . . . . . . . . . . . . 3

4.3 Grout - . . . . . . . . . 3 4.4 Horizontal Joint Reinforcing. . . 3 4.5 Bar Reinforcement . .......... . . . . . 3

5.0 DESIGN AILOWABLES . . . . . . . . . . . . . . 3

5.1 Stresses . ... . . . . . . . . . . . . . . . . 3

5.2 Damping . . . . . . . . . . . . . . . . . . . . . 4

6.0 ANALYSIS AND DESIGN . ....... . . . . . 4

6.1 Structural Response of Unreinforced Masonry Walls 4 6.2 Structural Response of Reinforced Masonry Walls. . 5 6.3 Accelerations . . . . .. . ....... . . .. . 8

6.4 Interstory Drift Effects . . . . . . . . . . . . . 8 6.5 In Plane Effects..... . . . . . . . . . . . . 8 6.6 Equipment...... ...... 9

6.7 Distribution of Concentrated Out of Plane Loads. 9

7.0 ALTERNATIVE ACCEPTANCE CRITERIA , * , , , . . . . . . 9

7.1 Reinforced Masonry . . . . . . . . 9 7.2 Unreinforced Masonry. . . . . . . . . . . . . . . 10

Tables 1 . . . . . . . . . . . . . . . . . . . . . 12

Notes to Table 1. . . . . . . . . . . . . . . . . 13

Table 2 . . . . . . . . . . . . . . . . . . . . . 14

Notes to Table 2 . . . . . . . . ... . . . . . . . 15

R-2/1

CRITERIA FOR THE RE-EVALUATION

OF CONCRETE MASONRY WALLS

FOR THE

MONTICELLO NUCLEAR POWER PLANT

1.0 GENERAL

1.1 Purpose

This specification is provided to establish design requirements and criteria for use in re-evaluating the structural adequacy of concrete block walls as required by NRC IE Bulletin 80-11, Masonry Wall Design, dated May 8, 1980.

1.2 Scope

The re-evaluation shall determine whether the concrete masonry walls will perform their intended function under loads and load combinations specified herein. Concrete masonry walls not supporting safety systems but whose collapse could result in the loss of required function of safety related equipment or systems shall be evaluated to demonstrate that an SSE, accident or tornado load will not cause failure to the extent that functions of safety related items is impaired. Verification of wall adequacy shall take into account support condition, global response of wall, and local transfer of load. Evaluation of anchor bolts and embedments are not considered to be within the scope of IE Bulletin

80-11.

2.0 GOVERNING CODES

For the purposes of re-evaluation, the American Concrete Institute "Building Code Requirements for Concrete Masonry Structures" (ACI 531-79) will be used except as noted herein.

3.0 LOADS AND LOAD COMBINATIONS

The walls shall be evaluated for the following loads.

3.1 Service Load Conditions

D + R + T + E

D + T + W

R-2/1 -1-

3.2 Factored Load Conditions

D + R + T.+ E' + Px

D + T + W'

3.3 Definition of Terms

D - Dead loads or there related internal moments and forces including any permanent equipment loads.

R - Pipe reactions during normal operating or shutdown conditions, based on the most critical transient or steady-state conditions.

T - Thermal effects and loads during normal operating or shutdown conditions, based on the most critical transient or steady-state conditions.

E - Loads generated by the operating basis earthquake.

W - Loads generated by the design wind specified for the plant.

E'- Loads generated by the safe shutdown earthquake.

W'- Loads generated by the tornado specified for the plant.

Px- Jet impingement load due to postulated pipe break.

NOTE: All walls studied were interior walls. Thermal effects were considered to be negligible. Wind loads do not affect interior walls. Loads T, W and W' were considered to be zero in this evaluation.

4.0 MATERIALS

The project specifications indicate that materials used for the performance of the work were originally specified to meet the following requirements.

4.1 Concrete Masonry Units

Hollow Concrete Blocks: ASTM C-90-66T Grade U-1 with a minimum net compressive strength of 2500 psi.

Solid Units: ASTM C-145-66T Grade U-1 with a minimum net compressive strength of 2000 psi.

R-2/1 -2-

4.2 Mortar

ASTM C-270: Type M - 2500 psi for Hollow Units

Type PL - 2000 psi for Solid Units

4.3 Grout

Materials proportioned to produce a grout having a minimum compressive strength of 1500 psi at 28 days.

4.4 Horizontal Joint Reinforcing

"Duro-wall" standard truss type. The thickness of the joint reinforcement measured during the recent inspection was 0.072 inches for the chord members and 0.040 inches for the web members.

4.5 Bar Reinforcement

Hollow Block

ASTM-A15-Intermediate Grade deformed Yield Stress 40 ksi

Shielding Walls

ASTM-A615 Grade 40

5.0 DESIGN ALLOWABLES

5.1 Stresses

Allowable stresses for the loads and load combinations given in Section 3 will be as given in this section based on the following compressive strengths:

Hollow Concrete Units V = 1200 psi m

Hollow Concrete Units f' = 1200 psi Grouted Solid

Solid Concrete Units V = 1200 psi

Stresses in the reinforcement .and masonry shall be computed using working stress procedures.

The allowable stresses for service loads given in Section 3.1 shall be the S values given in Tables 1 and 2 for reinforced and unreinforced masonry

R-2/1 -3-

respectively. The allowable stresses for the factored loads given in Section 3.2 shall be the U values given in Tables 1 and 2 for reinforced and unreinforced masonry respectively.

5.2 Damping

The damping values to be used shall be as follows:

Unreinforced walls

2% - OBE 4% - SSE

Reinforced walls

4% - OBE 7% - SSE.

6.0 ANALYSIS AND DESIGN

6.1 Structural Response of Unreinforced Masonry Walls

6.1.1 Out of Plane Effects

1. The wall shall be modeled as a finite element plate with appropriate boundary conditions. For a multimode analysis the modal responses shall be combined using the square root of the sum of the squares.

2. If the calculated stresses exceed the allowables in Step 1, the wall will be evaluated using the alternative acce'tance criteria.

6.1.2 Frequency Variations in Out of Plane

Uncertainties in structural frequencies of the masonry wall resulting from variations in mass,, modulus of elasticity, material and section properties shall be taken into account by varying the modulus of elasticity as follows:

Ungrouted walls - 1000f' to 600f' m m

Grouted or Solid Walls - 1200f' to 8OOf' m m

R-2/1

-- 1:1 1. - I I V

-4-

If the wall frequency using the lower value of E is on the higher frequency side of the peak of the response spectrum, it is considered conservative to use the lower value of E. If the wall frequency is on the lower frequency side of the peak of the response spectrum, the peak acceleration shall be used. If the frequency of the wall using the higher value of E is also on the lower frequency side of the peak, the higher value of E may be used with its appropriate spectral value provided due consideration is given to frequency variations resulting from all possible boundary conditions.

6.1.3 Combined In Plane and Out of Plane Effects

Provided both the allowable stress criteria for out of plane effects and the in plane stress or strain criteria are satisfied, the walls shall be considered to satisfy the re-evaluation criteria. If either criterion is exceeded, walls will be evaluated using the alternate acceptance criteria.

6.1.4 Stress Calculations

All stress calculations shall be performed by conventional methods prescribed by the Working Stress Design method.

6.2 Structural Response of Reinforced Masonry Walls

6.2.1 Out of Plane Effects

The following sequence of analysis methods will be applied.

1. Walls shall be modeled as a finite element plate with appropriate boundary conditions assuming the wall is uncracked. If the allowable stresses for an unreinforced wall given in Table 2 are exceeded, the plate will be assumed to crack and the moment'of inertia for a cracked section given in Sec. 6.2.2 shall be used over a cracked area. For a multimode analysis, the modal responses shall be combined using the square root of the sum of squares. If the calculated stresses exceed the allowables of Table 2, the wall will be evaluated using the alternative acceptance criteria.

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.6.2.2 Equivalent Moment of Inertia

6.2.2.1 Uncracked Condition

The equivalent moment of inertia of an uncracked wall (It) shall be obtained from a transformed section consisting of the block, mortar, cell grout or core concrete. (Note that a centrally reinforced wall has the same moment of inertia as an unreinforced section.) Alternatively if the mortar joint is assumed to crack or actually cracks the equivalent moment of inertia may be calculated by neglecting the mortar and block on the tension side.

6.2.2.2 Cracked Condition

If the stresses due to all load combinations exceed the allowables the wall shall be considered to be cracked. In this event the moment of inertia of a cracked section shall be used for the area of the wall that is shown to have cracked. Other wall areas shall be considered uncracked.

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6.2.3 Frequency Variations

Uncertainties in structural frequencies of the masonry wall resulting from variations in mass, modulus of elasticity, material and section properties shall be taken into account by varying the modulus of elasticity from 1200f' to 800f' . It is considered conservative to use tie lower value of E if the wall frequency is on the higher frequency side of the peak response spectrum. If the wall.frequency using the lower values of E is on the lower frequency side of peak of the response spectrum the peak acceleration shall be used. If the frequency of the wall using the higher value of E is also on the lower frequency side of the peak, the higher value of E may be used with its appropriate spectral value provided due consideration is given to frequency variations resulting from all possible boundary conditions.

6.2.4 In Plane and Out of Plane Effects

Provided both the allowable stress criteria for out of plane effects and the in plane stress or strain criteria are satisfied, the walls shall be considered to satisfy the re-evaluation criteria. If either criterion is exceeded, the walls shall be considered to satisfy the re-evaluation criteria. If either criterion is exceeded, the walls will be evaluated by the alternative acceptance criteria.

6.2.5 Stress Calculations

All stress calculations shall be performed by conventional methods prescribed by the Working Stress Design method.

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' 6.3 Accelerations

For a.vall spanning between two floors, the envelope of the spectra for the floor above and below shall be used to determine the stresses in the walls.

6.4 Interstory Drift Effects

The magnitude of interstory drift effects shall be determined from the original dynamic analysis.

6.5 In Plane Effects

If a masonry wall is a load bearing structural element shear stresses shall be evaluated and compared with the allowable stresses of Tables 1 and 2.

If the wall is an infill panel or non-load bearing element, shear stresses resulting from interstory drift effects will not be calculated. In this case, the imposed interstory deflections of Sec. 6.4 shall be compared to the displacements calculated from the following permissible strains for .service loads. For factored loads, the strains shall be multiplied by 1.67. The deflections shall be calculated by multiplying the permissible strain by the wall height.

Unconfined Walls (1) - 0.0001

Confined Walls (2) - 0.0008

Notes: (1) An unconfined wall is attached on one vertical boundary and its base.

(2) A confined wall is attached in one of the following ways:

(a) On all four sides. (b) On the top and bottom of the

wall. (c) On the top, bottom and one

vertical side of the wall. (d) On the bottom and two vertical

sides of the wall.

If an infill panel or non-load bearing element is subjected to both interstoty drift effects and shear stresses due to inplane loads from equipment or piping, the following criteria shall apply.

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actual inplane actual intershear stress + story deflection <1l allowaole inplane allowable intershear stress story deflection

A more refined analysis may be performed if necessary.

6.6 Equipment

If the total weight of attached equipment is less than 100 Ibs., the effect of the equipment on the wall shall be neglected. If the total weight of the equipment is greater than 100 lbs., the mass of the equipment shall be added to that of the wall in calculating the frequency of the wall.

Stresses resulting from each piece of equipment weighing more than 100 lbs. shall be combined with the wall inertia loads using'the absolute sum method. The SRSS method may be used provided its application is justified.

Stresses resulting fromn the equipment shall be calculated by applying a static load consisting of the weight

. of equipment multiplied by the peak acceleration of the

response spectrum for the floor level above the wall. If the frequency of the equipment is known, it may be used to determine the'static load.

6.7 Distribution of Concentrated Out of Plane Loads

6.7.1 Plate Action

For plate action, local moments and stresses under a concentrated load shall be determined using appropriate analytical procedures for

plates or determined numerically using a finite element analysis.

6.7.2 Localized Block Pullout

For a concentrated load, block pullout shall be checked using the allowable values for unreinforced shear walls in Table 2. This allowable shall be used for both reinforced and reinforced walls.

7.0 ALTERNATIVE ACCEPTANCE CRITERIA

7.1 Reinforced Masonry

Where bending due to out-of-plane inertial loading causes flexural stresses in the wall to exceed the

allowable stresses .for reinforced walls, the wall

can be evaluated by the "energy balance technique."

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7.1.1 Effects on Equipment

If the deflection calculated by the energy balance technique exceeds three times the yield deflection, the resulting deflection shall be multiplied by a factor of 2 and a determination made as to whether such factored displacements would adversely impact the function of safety-related systems attached and/or adjacent to the.wall.

7.1.2 Effects on Walls

The maximum deflection in the wall due to outof plane inertia loading shall be limited to 5 times the yield displacement. The yield displacement shall be calculated by reinforced concrete ultimate strength theory, and the masonry compression stresses of 0.85f' based on a rectangular stress distribution sWall be used.

7.2 Unreinforced Masonry

When, due to out-of-plane loading, the allowable stresses for unreinforced masonry are exceeded, the arching theory for masonry walls may be used to measure the capacity of the walls. Due regard must be paid to the.b6undary conditions.

7.2.1 Limited Deflection

The deflection of the three hinged arch could be determined by assuming that the arch members are analogous to regular compression members, in a truss. The method of virtual work (unit load method) may be used to compute the deflection at the arch interior hinge. The calculated deflection should not be more than 0.3T where the "T" is the thickness of the wall. A determination should be made as to whether such calculated displacments would adversely impact the function of safety-related systems attached and/or adjacent to the wall.

7.2.2 Allowable Stresses

The total resistance of the wall (f) shall be calculated using the following stresses:

I. Tensile stress through the assumed tension crack shall be 6 /?'E for grouted walls or ft for'ungrouted walls.

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II. The crushing stress of block material = 0.85f'

By applying a factor of safety of 1.5 to the total resistance (f) as calculated above, the allowable load on the wall is limited to f /1.5.

7.2.3 Boundary Supports

The boundary supports should be checked if they are capable of transmitting the reaction forces applied to them. The effect of support stiffness on the reaction forces should be considered.

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Table 1: Allowable Stresses In Reinforced Masonry

Description_

Compressive

Axial 1

Flexural

Bearing

On full area On one-third area or less

Shear

Masonry Takes Shear

Flexural Members 2

Shear WaIls 3

MVd I M/Vd= 0

Reinforcement Takes Shear

Flexural Members

Shear Walls

M/Vd 1 1 M/Vd = 0

Reinforcement

Bond

Plain Bars Deformed Bars

Tension

Grade 40 Grade 60 Joint Wire

Compression

S Allowable 1 Maximum

(psi) CDsD I

4

0.22f'm 0.33f'm

0.25f'm 0.375f'm

1.1 v ~

0.9

2.0 VI'1

3.0 /F

1.5 /Fri 2. 0 1 '

1000 1200

900 1200

50

34 74

150

75 120

60 140

20.000 24.000 .5Fy or 30.000

0.4Fy

U Allowable Maximum

(psD (psDi

0.44f'm 0.85f'm

0.62f'm 0.95f'm

1.7 A

1.5 fm 3.4

4.5

2.5 /f 3.4 /f'm

2000 2400

1800 2400

75

56 123

225

125 180

80 186

0.9Fy 0.9Fy 0.9Fy

0.9Fy

(psD) fpoD

Notes to Table 1t

(1) These values should be multiplied by h 3

(2) This stress should be evaluated using the effective area shown in Fiqure 1

Cd OR ReaAR SPACWpG P7HC'HEYER /T LE$3 A RUWIN/IG 4'OND

-4RA ASUMTVED FCrv IN FZEXURAL Cn/. 110O',o.c e/Q,4" To FACE.C

FIGURE 1

(3) Net bedded area shall be used with these stresses. (4) For u/Vd values between 0 and 1 interpolate between the values given for 0 and 1.

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Table 2: Allowable Stresses In Unreinforced Masonry

Allowable Description(pD

Compressive

Axial 0.22f'm Flexural 0.33f'm

Bearing

On full area 0.25f'm On one-third area or less 0.3751'm

Shear

Flexural Members 2, 3 1.1 F Shear Wails 2 0.9f F

Tension

Normal to bed joints

Hollow units 0.5 0

Solid or grouted 1.0 /m

Parallel to bed joints,

Hollow units 1. 0 0

Solid -or Grouted 1. 5 /m--F 0

Maximum

(psD

1000

1200

900

1200

50'

34

25

40

50

80

U

Allowable Maximum pZI

0.44f'm

0.85f'm

0.62f'm

0.95f'm

1.7/f'm

1.35/f'm

0.83 / 1.67 /

1.67 /j

2.5 0

2000

3000

2250

3000

75

51

42

67

84

134

Notes to Table 2:

(1) These values should be multiplied by 1 h 3 (2) Use net bedded area with these stresses. (3) For stacked bond construction use two-thirds of the values specified.

(4) For stacked bond construction use two-thirds of the values specified for tension normal to the bed joints in the head joints of stacked bond construction.

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13.0 NRC COMMENT

Provide details of proposed wall modifications with drawings and explain how these modifications will rectify wall deficiencies.

RESPONSE:

As a result of the block wall analyses performed for the Monticello Nuclear Generating Plant, four drawings were prepared. These drawings show the modifications for the block walls. (Reference Bechtel Job No. 10040 Drawing C-2018, C-2019, C-2021, and C-2022).

The following is an explanation of how these modifications will rectify wall deficiencies.

Wall 212 was originally analyzed as a plate with the top free and one side free. This resulted in unacceptable stress levels. The wall was reanalyzed with the previous free side pinned at the top and equivalent springs placed along the free side. The stress levels were found to be acceptable.

A truss was designed to carry the resulting loads with the required stiffenesses used in the wall analysis.

Wall 222 was originally analyzed as a plate with the top free and one side free. This resulted in unacceptable stress levels. The wall was reanalyzed with the top pinned. The stress levels were found to be acceptable.

Braces were designed to carry the loads and were placed along the top of the wall. Stiffenesses and connection are adequate to simulate the assumed pinned conditions.

Wall T311 identified during the field survey for the NRC Bulletin 80-11 is subject to jet impingement from pipe line C4A-16-GB as identified on Bechtel Job #5828, Drawing No. M-223.

To prevent the collapse from the jet forces a shield has been provided to back up the wall at the postulated pipe break. The shield is designed to carry the full load from the jet force.

Wall T322 identified during the field survey for the NRC Bulletin 80-11 is subject to jet impingement from pipe lines C4A-16-6B and C4B-16-6B as identified on Bechtel Job #5828 drawing No. M-223.

To prevent the collapse of the wall, from the jet force, shields were provided. These deflect the jet forces from the postulated pipe rupture. They are designed to carry the full load from the jet force.

The remaining details have been addressed in an inspection summary report No. 50-263/81-13, Docket No. 50-263 by the NRC inspector R. B. Landsman on April 22 and July 14, 1981.

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Enclosure (13) Drawings - Supplied with NRC NRR Project Manager's Copy

Bechtel 10040 C-2018 Rev 3

C-2019 Rev 3

C-2021 Rev 1

C-2022 Rev 3

(NF 92292)

(NF 92293)

(NF-92295)

(NF-92301)

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14.0 NRC COMMENT

Provide a schedule for the proposed wall modifications.

.RESPONSE

All wall modifications have been completed per the provisions outlined in our response to IE Bulletin 80-11.

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forwards addl info re ie bulletin 80-11, 'masonry wall design,' in … · 2012-12-06 ·...

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